* Not all PS4 games can run on PS5. Granted, it's only a few edge cases. But you still need to pay the PS4>PS5 upgrade if you want to avoid bottlenecks.

* PS3 games and the like require a 150+$ yearly subscription, and it's streaming for many of them. No thanks.

* No PS2/PSP/Vita compatibility, heck no emulation at all.