PS3 base models were BC to PS2 (and PS1) even before they added digital-purchased emulated copies.
PS Vita has a built-in PSP that can play digital versions of those games as well as PS2 ones.
PS4 had a very limited selection of PS2 games released digitally for it.
PS5 is BC with PS4.
They could do a lot better, though. Their digital offerings are extremely limited and have yet to tackle the issue of emulating the cell processor at reasonable speeds.
PS2 base models were BC to PS1
PS3 base models were BC to PS2 (and PS1) even before they added digital-purchased emulated copies.
PS Vita has a built-in PSP that can play digital versions of those games as well as PS2 ones.
PS4 had a very limited selection of PS2 games released digitally for it.
PS5 is BC with PS4.
They could do a lot better, though. Their digital offerings are extremely limited and have yet to tackle the issue of emulating the cell processor at reasonable speeds.