I think some of it is boasting, the whole billion polys being crunched to 20 million is really just a decimation algorithm at this point probably being run on some custom and special processing units, in the long run, it will be interesting to see how this translates to the PC sphere and whether or not we are starting to move into the world of even more GPU threads or processor units for high-specification games. It's certainly interesting to watch, especially given the uptake of photogrammetry within gaming.
8K textures are pure boasting, apart from rare and specialist areas, utterly useless at the moment, water physics on a small sample, and tbh it didn't look awesome, so more word-salad and buzzword hyping here.
Rumour has it that the PS5 specific SSD/Memory interoperability stuff is what makes loading etc less of a problem for this stuff, again, will be interesting to see how this starts to translate to the PC sphere.
It's nice to see the software world driving the hardware world phase again, I think we've been away from this for too long in some ways.
It's easy to miss some of the points of discussion when everyone is engaging in 'game engine jingoism' Duion is correct in the assertion that developer usage of new technology does lag somewhat, we do have several examples of this over the years. He is also correct that in some ways this does raise the bar for artists, sadly at the same time, it lowers the bar knowing that the algorithms can clean up the 'mess' to a degree.
It would be much more interesting to see how this stuff actually works in practice. It's easy to get a good tech demo when you have the game developers the engine developers and the hardware developers all working together on a single project, but this is a million miles away from 99% and probably a few decimals thrown in for good measure of games being developed right now, I mean that specific demon has probably more man-hours in that 3-minute section than most indie games ever get in total.