GRMember

Xbox 360 emulation on the modern Xbox is similarly a situation where support was rolled out title by title over a long period of time, and most Xbox 360 titles are still not whitelisted for support. A similar model is most likely what Sony is working on. The reason it has been so difficult for them has to do with the really unusual and convoluted architecture of the PS3 hardware. What made it a mess for developers to support back then makes it hard to emulate correctly now.

The PS1 Classics that they have listed for PS4 and PS5 actually are listed for free if you purchased them on PSP or PS3 or PS Vita though. Same goes with the PSP titles. Like, it's annoying that more titles aren't supported yet, but they really haven't made us rebuy the emulation titles we have bought before.

While I doubt hundreds of PS3 games will become compatible overnight the good news is they actually do have a pretty good track record of not making people repurchase the same version of the same game. The PS1 Classics they've added to PS4/PS5 that I had bought before when they were on PSP/PS3/VITA have always shown up listed as FREE for me. Similarly, it hasn't made me rebuy PSP Classics it has listed if they were titles I had already bought digitally on the PSP or the PS VITA.