Wine can be set up in a similar way, but Valve's default setup is designed to for use with Steam first and foremost.
A bigger issue is that the Steam Deck touchpads don't work without Steam being open. A more open approach would have been to write independent driver software for the touchpads.
Valve's far and away better than Nintendo, but has still designed the Steam Deck to be heavily reliant upon Steam to function. The Steam Deck is priced in a way that anticipates increased consumer usage of Steam, but in isolation of Steam, it would be more usable as a Linux PC if it were more software-agnostic.