I love the Steam Deck because it feels like a consumer electronics device: it has the reliability of Linux but not the sweat. The Steam Deck is the only device I've seen that works 100% perfectly with Airpods, for instance, including Apple devices.
I was at Best Buy the other day and saw an ASUS device that looked pretty cool until I picked it up and saw a Windows desktop with fonts not scaled appropriately for the size of the device. Like, wazzup? Steam Big Picture turns my big Windows machine at home into a game console and does the same for my Mac Mini. How is it you can have the back of frickin' Microsoft and not be able to do the same?
Not to say that Steam isn't packed with features that are valuable to many gamers, but just having a great selection of games that "just work" and knowing I can enjoy my investment on the devices I have now and devices I get in the future is worth a lot.