This is going to make games shittier.
phone gaming opened up the floodgates for phone game developers, so even on Steam, those shitty phone games end up taking up advertising space (because everyone can play Chode Puzzle Game XIV, why not market it on Steam too? Steam has no quality standards, so it won't exclude them.)
Steam Deck is the same thing, any new platform for mediocre games means more mediocre games development and then more mediocre games taking up advertising space.
industry is so saturated with shitty games, even AAA developers are dropping dogshit and they're so insulated from criticism by their publishers' fake consensus and fake reviews they probably think everything is great.
Anyone that criticizes their mediocre dogshit is just an internet troll.