“We keep in mind the engineering specialized for the PS5, as we produced the device. In the midst of that, the PS4 already has 100 million players; we thought they ought to want to play PS4 titles on the PS5 as well indeed, so we included compatibility with the PS4. While implementing that, we also focused our efforts on taking in the high-speed SSD and the new controller DualSense at the same time.” said Jim Ryan.
“So, unfortunately, we could not achieve compatibility with those formats,” Ryan continued.
Whilst the PS5 won’t play PS3, PS2 and PS1 games at launch, it’s worth mentioning that PlayStation Now (which isn’t available in Australia) does play PS3 games, so it’s possible we’ll see them become playable through cloud streaming at some point.