I bought one on the premise of both PS5 and Xbox Series X releasing 8K content.
We got:
The Touryst - Not a bad game, but not needing 8K either.
Ori and the Will of the Wisps supported 6K, GREAT game.
On the PS5 Pro (through PSSR upscaling)
F1 24 (at 60 FPS)
Gran Turismo 7 (at 60 FPS)
No Man’s Sky (at 30 FPS)
Pure Pool Pro (at 30 FPS with ray tracing)
[REDACTED] (at 60 FPS)
The Callisto Protocol (at 30 FPS with ray tracing)
And that's it...