The Steam Deck is all about singleplayer games on the go, requiring an active internet connection breaks that.

This group believes that "Singleplayer gameplay requires an active Internet connection" should be grounds for an automatic Playable on Steam Deck. Not Verified.

This also applies (depending on the severity) to "This game's first-time setup requires an active Internet connection", which is requiring third-party accounts & DRM, Kernel Level Anti-Cheat, etc. If it needs internet the first-time, it can ask for it later down the line when you least expect it.