[mst]

Pentax does (in the K-3iii) eye recognition with 307,000 RGBIr pixels. Remember that thomass said "it's not possible"? It is. You're still debating around this fact.

No, you are. I'm trying to tell you that, no matter what the manufacturers claim, even with a 300k sensor it will not be usable in real life. And that's not an assumption, it's my opinion based on more than 10 years of experience with Nikon 3D tracking.

You are clinging to the words Thomas used ('is not possible'). Feel free to insist that you believe it is possible, because some marketing department tells you so (Pentax and/or Nikon). Allow me to still disagree based on the experiences I made with the available systems. I am pretty sure that is what Thomas intended to say: with the current technology, it's not possible to do in a way that is actually working and/or useful.

How well it works in this implementation, it remains to be seen... but this isn't the best a DSLR can do! And not all mirrorless can reliably focus on the eye instead of eye lid/lashes....

The D6 AF is generally regarded as one of the best there has ever been. So, the youtube video gives you an impression what one of the best AF modules on the market can do: it can not reliably focus on a subject's eye. And no one actually using the camera would expect that, to be honest. That's not what 3D tracking was made for... it marvels in other regards, though.

Then, there's the elephant in the room - that DSLRs can evolve beyond the current configuration. Shouldn't we wish them to do so?

Yeah, I'd love to see that. The issue is: why would any of the manufacturers (all of which seeing a severe market decrease, some of them in severe trouble already) invest into that, when the whole market is moving in a completely different direction? That's why I wrote about the dead-end: not because there is no potential left to improve DSLRs. But because only a minority of potential buyers is actually interested in it. And because there is a much bigger market now (mirrorless) with bigger opportunities to earn money (at all, in some cases... in other words: to survive as a brand).

Spoiler: it's not just about the cameras, the new mounts allow for much better designs. Any of the Z mount primes or high end zooms I've used so far make their F-mount counterparts look really poor.