Things you don’t need new hardware for

I’d like more games designed exclusively for the PS5 (and Series X) long before talks of a Pro model for either system. I’m not talking about better looking games, but games that technically could not function on previous gen consoles. — Kang81

The real answer is all the quality-of-life ecosystem stuff that Xbox has. 

Free cloud saves instead of locked behind a PS Plus subscription and a toggle

Free next-gen upgrades from PS4 to PS5, automatic install of the correct version depending on console—no more having to pick the correct version (AKA Xbox Smart Delivery)

Cross-save from PS5 to PS4 (currently you can “upgrade” PS4 saves to PS5 saves, but not the other way around)

Included PC and PS4 copies with every PS5 game, allowing installation on any platform (AKA Xbox Play Anywhere)

Save syncing between PC, PS4, and PS5 versions of a game

DualShock 4 controller support for PS5 — Nick Ha

Sony needs to go back and patch their existing games to properly support PS5. Why is The Last Guardian still capped at 30 FPS? Why has Bloodborne not been updated in any way? Much of Sony’s first-party library looks and runs like crap because it’s capped at low resolutions and framerates from the PS3 and PS4 days. — Jerykk