Exactly! I already do a lot of inhome streaming via Steam Link, so I'll likely be using that feature a lot.
My main thing is, if the Steam Deck pans out, buying a game off Steam will give me:
A) the PC build of the game, which is commonly the best performing/best looking version
B) the best performing native handheld version of the game (given Nintendo's presently deficient spec), which I can further customize to my liking
C) the ability to play A over in-home streaming anywhere in my house, albeit limited to 1080p
All of that, and my save presumably updates to the cloud anywhere I play? That is frankly incredible value. I'm just hoping that Gabe and co. don't mess up the implementation of the user-friendliness/QOL improvements this thing needs to make a good first impression as a pseudo "console", I'm optimistic they have it figured out.