The example with Android makes no sense as a argument in our discussion.
The steam deck is a hand-held game console - doesn’t matter what OS is it uses
Wrong. It does matter. Plus, it matters what software and what configuration it uses the moment it gets counted in the stats.
The discussion is not about what you try to tell. You can say what you want, it does not matter that the Steam Deck uses hardware that is PC and software that is a hybrid of Desktop and Gaming operating system. And when going to the web with a web browser, then the Steam Deck is in Desktop mode, and therefore seen as a Desktop PC. Not only act it like that, the functionality is a Desktop PC.
The Steam Deck has two modes if you forgot that, and we are talking about the Desktop PC mode. Which is what the stats are all about.