There's a huge cost savings with steam though - when I bought my steam deck I instantly had 600+ games available for it. I didn't have to go out and buy separate copies because it's on a new device.
Also given that plenty of games go on sale pre launch or on the first sale, there are humble bundle deals etc, steam is way cheaper unless you *only* want to play the newest AAA games. My two games of the year right now I paid $40 combined, brand new, day of release. You're not getting that on a ps5 exclusive anytime soon.