I would love to see Sony add PS3 and PS4 BC in PS5, and PS1 and PS2 compatibility in PS4. You would hope they do SOMETHING when microsoft is making great strides in BC.
In any case, PS Now is not very good for many internet connections in the US, and doesn't seem to be a very popular service. I wish they would pull something where you could just buy an unlimited access to a game or have it recognize a disc. I don't want to pay a subscription, but there are some games I'd love to have access to; like Ninja Gaiden Sigma, Red Dead Redemption, and Resistance 3 for example. (I'm considering buying a Xbox One X for those games being BC.)
I realize there's a challenge in emulating all the previous playstation systems' architectures, but existing emulation on ps1-3 is all pretty stellar. I wish Sony would just buy into that tech and its possibilities for better frame rate and resolution instead of a streaming service that's severely limited. I'm not gonna poo poo PS2 on PS4. It's nice to have HD PS2 games with trophies. Bully in particular has gotten a lot of playtime from me. Rockstar has given it good support, but come on Capcom, Sega, and Sony...There is a gold mine of classics that could be made available.
I'd be pretty satisfied with Haunting Ground, Viewtiful Joe, Timesplitters 2, etc.