There are some very vocal people who will tell you that proton is just a stopgap measure, and shouldn't be relied on for the future of Linux gaming.
That said, I know the devs have been putting in effort/patches to make sure the proton/steam deck experience works well, and I consider that just as good. All I really want from devs is actual support of the Linux platform, and if they choose to do that through a tool like proton I'm ok with it.