Windows, even on a desktop computer, is still a horrible experience for gaming.
I grew up with PC gaming, and also used Linux as my only OS for over a decade, so I know how to tinker.
But I'm now an adult exhausted from a full time mentally taxing job. I have all the toys I want, but I simply don't have the energy to use my $3k gaming PC and would rather use a gaming console, which I consider a Steam Deck to be. Valve did something magical when they managed to create a console experience around PC games, and that is the only selling point of a Steam Deck, to me. All the competitors like RoG Ally are not an alternative by any stretch of the imagination.