I don't know. Power aside, PS4 is a legacy console now. Rebirth struggles a little on PS5, so I don't know what magic they'd have in store for Steam Deck. We are already halfway into the PS5 generation now. I'm already hearing they are starting to have talks about PS6. I know the deck is weaker, but this was made with the PS5 in mind and the more legacy outdated consoles we send it to may just hold back the product.
