Sans Mirror  

The Internet is a harsh place. You're left on your own to try to sort out the disinformation from the real information. To that end, let me once again tackle a few myths surrounding mirrorless cameras that seem to just keep propagating and replicating themselves, much like a virus.

1. Mirrorless cameras have poor battery life. This myth tends to revolve around CIPA test figures. The CIPA standardized testing basically is this: "take a picture every 30 seconds while leaving the camera fully active during the test; use flash every other picture if the camera has one built in." Because mirrorless cameras would have their display run the entire time during such a test, while DSLRs don't have a power hungry display active all the time, the CIPA test numbers really start to tell you how long you can continuously use the camera, not how many shots you can take. For instance, a CIPA number of 360, which is pretty typical for a mirrorless camera, would suggest that the camera can run continuously for three hours, max. In real life, of course, you may be shooting more than one shot every thirty seconds (sports), not shooting every thirty seconds (casual, travel), of some other variant where the display does get shut down for longish periods. Every variation on those themes will net you more shots per charge than CIPA suggests, sometimes considerably so. I regularly get 2x to 3x the suggested shot capability on pretty much all my mirrorless cameras, sometimes much more. Oh, and by the way, are you really taking 360 shots a day in the first place? Most folk can get by with one battery and charging it each day, but carry an extra just to be safe. Not a big deal.
2. The electronic viewfinders (EVF) on mirrorless cameras have terrible lag. Certainly the first mirrorless cameras had more lag than current ones do, but I'm not sure I'd ever characterize it as terrible. Today, generally the viewfinder lag is no more than 60Hz, which, by the way, is faster than the actual mechanical shutter lag on many low-end DSLRs. Doh! In reality, there's a chain of things that happen: (a) you're watching for something and respond to it (human lag), (b) you press the shutter release (in DSLRs the mirror needs to moved out of the way and the shutter opened), (c) the camera takes a photo. I wouldn't judge mirrorless cameras today to be any slower at a-to-c than DSLRs. Indeed, some are better in actual use, as they don't ever blackout the viewfinder (e.g. Sony A9). 
3. EVFs aren't good for your eyes. This plays off another Internet myth that gets circulated, that all displays are bad for your eyes. Were that actually true to the level where you'd need to fight against having a display provide information, we'd be seeing huge volumes of eye problems at optometrists that we've never seen before. Having read a large number of studies in this arena, one problem I see is that not all factors and variables are being controlled. While I have no doubt that artificial displays can have some impact on vision, I also have no doubt that plenty of other situations can have impact on vision, too, such as not shielding eyes from brightness or UV. Just as you wear sunglasses for those, there may come a time when you wear some type of lens for EVFs. (And no, I don't think the "blue filter" optics that get promoted on the Internet are exactly the right answer.) Another sub-complaint here that needs to be dismissed is that "you're looking at a screen that's only inches away from your eyes." That's a naive interpretation. The optics in modern viewfinders, both for DSLRs and mirrorless cameras, attempt to place the perceived distance of what you're looking at about a meter away. And let's not talk about presbyopia ;~).
4. Mirrorless cameras have terrible, small, or fiddly controls. No doubt there are mirrorless cameras that don't have a reasonable hand grip, have controls scattered in unusual places, use buttons that are small and difficult to find by touch, have menus that are tough to understand or navigate, or aren't particularly configurable. Back when it was mostly the consumer camera engineers designing mirrorless bodies, a lot of consumer nonsense made it into those early mirrorless cameras. These days, the systems have all matured, and with perhaps the exception of menu nomenclature and organization, I'd say you can pretty much set this myth aside.
5. Image Noise or Depth of Field is a problem. This myth originated from the fact that mirrorless started with smaller sensor sizes when DSLRs were in the midst of their full frame heyday. Today, however, you can directly compare apples-to-apples in terms of sensor size and capability, and if you do, you find that mirrorless really doesn't have any penalty at all. True, if you pick an m4/3 mirrorless camera over a full frame DSLR, then there are some differences you need to be aware of, but apple-to-apples there is no difference.
6. Mirrorless cameras aren't as well built as DSLRs. Well, if you're talking Canon 1DX Mark III or Nikon D6, I suppose that might be somewhat true, as those DSLRs are built like tanks, and few mirrorless camera to date have really matched that level of build quality other than perhaps the E-M1 Mark III and E-M1X. But in terms of the mainstream of mirrorless cameras, most have robust structures and reasonable weatherproofing these days. 
7. Autofocus isn't as fast or responsive. This is a little bit tricky, because "fast" isn't the sole attribute on which you need to judge autofocus. However, once most mirrorless cameras went to phase detect autofocus on the image sensor—exceptions still exist at the lower end of the spectrum, and Panasonic still sticks with their DFD focus system—things evened up very quickly between mirrorless and DSLR in terms of the speed at which focus is initially acquired. Generally, cameras with dedicated processing power for focus, which includes a few top DSLRs and more and more mirrorless cameras, focus not only faster, but track focus better. In the mirrorless world, the top focusing cameras right now would be the Canon R5 and R6, plus the Sony A9 Mark II and A1. Some, like the Nikon Z6 II and Z7 II, are not much behind those. But looked at a different way—from the viewpoint of consumer DSLRs—most mirrorless cameras these days focus more than fast enough, and may even beat some of those low-end DSLRs.
8. Mirrorless cameras don't make good sports or wildlife systems. This is related to the previous myth, but given that the previous myth is indeed a myth, you can probably guess my comment here. Anyone paying attention has known that I've been using a mirrorless camera at least part of the time for wildlife photography for about a decade, and have been taking wildlife and sports photos with mirrorless cameras quite often in the last few years. Do I prefer my Nikon D6 over a Nikon Z6 II for sports? Yes, but not by as wide a margin as you might guess. Would I be disappointed if I had to use a Sony A9 Mark II instead of my D6? Not in terms of performance.
9. Phase Detect on sensor reduces sensor capability. No. Not in any way that most people would ever encounter. Many of the "low-level banding" complaints are actually just attempts by DSLR users to find something to criticize about mirrorless cameras. Practically speaking, I've not had any image ruined by "low-level banding," and on the early Nikon Z bodies, there's a way to simply avoid that in the first place (use 12-bit raw). 
10. Lens choice is a problem. Any new mount has the chicken-and-egg problem. At one time  every mirrorless camera system had a "new mount." The DSLR systems had decades to round out lens lineups of 60+ optics (plus older no-longer-in-production optics, as well). On day one of any new mirrorless system, each started with a half dozen or fewer lenses, so, yes, you can see how this could be an issue. However, time has transitioned this complaint to that of a myth, even for the most recent mounts (e.g. Nikon Z). The oldest mirrorless mount, m4/3? Plenty of lens choice, with a lot of redundancy, too. The oldest full frame lens mount, Sony FE? Plenty of lens choice, with lots of third party support. Canon RF and Nikon Z? Both systems launched with really good lens adapters that let you use your DSLR lenses, and each is running at the rate of about 8 new lenses a year. The Z mount, for instance, has 16 currently available Nikkors, over 50 third party lenses, and hundreds of Nikkors that can run on the FTZ adapter available already. I'd argue that "lens choice" is not one of the mirrorless camera issues you should be worried about.

Mirrorless cameras are here to stay, and they're only going to get better. Most of the myths I describe above are (sometimes blatant) attempts at dismissing that notion. I say judge for yourself based upon real information and handling of a camera yourself. You might find that you've had a bias that was keeping you from exploring what's possible with the latest photographic gear.