PS3 is the only Sony console not to have significant backwards compatibility support on newer lines of their product. PS2 played all PS1 games, 3 played all PS2 and PS1 games at first, then all PS1 games after redesign. PS5 plays all PS4 games. There’s no reason to believe PS6 or whatever won’t play PS5 and likely PS4 games also.
PS3 is the only Sony console not to have significant backwards compatibility support on newer lines of their product. PS2 played all PS1 games, 3 played all PS2 and PS1 games at first, then all PS1 games after redesign. PS5 plays all PS4 games. There’s no reason to believe PS6 or whatever won’t play PS5 and likely PS4 games also.