Speaking of past-generations' physical backwards compatibility, we need a unified front on the digital side, too.
Thankfully, Sony is mostly on top of this, and if you've picked up a PS Vita or any of the PlayStation's "family" of systems, your purchases transfer effortlessly.
Bought a copy of Hotline Miami on PS3? Here's your Vita edition, ready to go.
Indie studios are the best at this stuff by a landslide, mainly because they're not trying to sell you a remake or remaster, though the same goes for a handful of larger studios' titles. However, as Sony and a handful of publishers have chosen to release "HD versions" of their classics, rather than just making the game itself work in the console or honour a past-gen purchase, let's NOT see "4K editions" of games we've already bought.
Instead, like how the PS4 Pro automatically renders games in higher quality or adds specific quality-of-life improvements like more populated open-world areas or better textures, everything we've paid to work on PS4 should automatically work on PS5.