Bazzite does include the Steam frontend but that's a proprietary system, it's not something that the Linux/FLOSS community came up with. The KDE folks are starting to look into remote-control focused "10-foot" media center interfaces (see the Plasma Bigscreen project) that are also somewhat applicable to gamepad control (though these handheld devices generally come with touchscreens too, and this creates additional affordances) but that's a bit of a too little and too late situation. We need far more than that to make this novel class of devices usable for genuine production uses.