It also depends on the audience. A lot of people might not be comfortable installing a different OS. Steam Deck is ready out of the box.

Personally, I have installed many OSes many times, so I am comfortable doing it to a handheld device. But the inputs on the Steam Deck would stop me from buying any alternatives. SD has so many options, full Xbox layout, track pads in either side, four paddles on the back, gyro, and the two "menu buttons". And they all feel super premium!

The last thing I'll say is about the support of all of this. I have only owned two valve made physical products at this point, Steam Deck and Steam Link. The updates for Steam Link continued far after the product was discontinued. The amount of bugs on the Steam Deck that were fixed via an update the day following it's report is truly astonishing. I have owned 3-4 ASUS ROG products and after the last keyboard I owned (how do you messup a keyboard?!?!) I decided it would take some serious innovation to get me to buy another product of theirs again. I have also owned two different models of GPD win, very unimpressed but the quality of the inputs so I sold them very fast. I can't speak to any other handheld but I can say I feel very comfortable with Steam backing the Deck.