That issue will be true on any linux platform because Epic Games is a nasty company that doesn’t care about consumer friendly practices. How will this device get around that?

https://www.gamingonlinux.com/2023/12/fortnite-on-linux-steam-deck-not-until-tens-of-millions-of-users/?n=@

Regardless, to say that the Steam Deck is locked down to the steamverse, is such a weird thing to lie about. You can install basically anything on Steam Deck:

https://www.gamingonlinux.com/2024/01/nonsteamlaunchers-for-other-stores-on-steam-deck-adds-automatic-game-shortcuts/