I think that overall Mirrorless still has a long way to go, as per my experiences via Sony A7 and Fuji X cameras. Sony at the moment is highly active and is releasing camera after camera and has a lot of hype generated by the forums and youtube videos of early adopters, as well as people from press events. Yet I don't see many Mirrorless cameras at pro events, and the clatter of clicks at Presidential briefings leads me to conclude that they're thin on the ground there as well. Where they seem to be making an impact is with enthusiasts. The point is irrelevant however.
My point really is that the high rate of iteration we're seeing with Sony is a symptom of Mirrorless' lack of capability. Put another way, DSLR's have developed from film cameras and their capabilities have evolved over time. Mirrorless is attempting to do in less time and fewer generations what the mature DSLR's have done for years. And it shows. I believe Mirrorless is still one or two cycles from truly challenging DSLR's. And I'm not alone in this. I cite ByThom's excellent analysis of mirrorless cameras as case in point (see latest comparison D70 vs A7III). And DSLR's are not a stationary target, as the Nikon D850 has shown, incorporating many (but not all) of the advances of mirrorless into it's design, while maintaining the advantages and DNA of Nikon.
As I mentionned on another forum post I will be selling my Sony A7RIII because it is simply too cumbersome to use. Ironic, a small camera cumbersome! I know, I know.. might start a flame war here. However FOR ME it takes away too much of what I enjoyed about DSLR's while not giving me enough Mirrorless magic. Sure the EVF is amazing and way better than using an LCD on a D850. Sure the stabilised sensor makes using older manual focus and unstabilised AF lenses more practical. But the overall package is lacking in too many areas, and one very obvious one. Hold one, and you will know within 10 seconds if it is for you. And if it is, Im happy for you, truly I am. However ergonomically it is too big of a step back.
So I stand by my argument that mirrorless is simply not ready. And the high cost of entry will burn many a consumer. Prices for Sony FF mirrorless are decreasing minute by minute. The A9 announced middle of last year is already $1000 off! Hefty premium to pay for being an early adopter. The A7RIII is now $200 off, and a lot less on EBay. The A7III is priced more reasonably, but don't be fooled. As more and more use it and compare it to the FF DSLR cameras (where prices have already dropped because of age) they will also take a hit on pricing. Simply put the mirrorless cameras are even more consumer than high-end DSLR's. We early adopters are paying dearly for it. I purchased my D810 at signicant discount 2 years ago and sold it for exactly what I paid for it a month ago. Try that with a A7RII? So we have a value discrepancy as well as capability issue here as well. Simply put Mirrorless are cheaper to make, and their used prices are reflecting this reality.
Yes, I know used prices are supply and demand, but there is an intrinsic value that we place on things as well, and that intrinsic value has to do with percieved quality. And that equation does not bode well for Sony in the long term. My prediction.. their prices will come down substancially at the next upgrade round, and their capability will increase to reach DSLR like levels. In the mean while DSLR's will mimic Mirrorless where they can while maintaining their own substantial advantages. End result? Mirrorless will not be takng over the photography world anytime soon. Unless Nikon or Canon decide otherwise :-)