Obviously their dark patterns are not sufficient to drive away enough users and this has been the case for decades. Nothing new to see here, it's the same old Microsoft of yore.
* macs, which cost an arm and a leg and aren't necessarily better if you've got an axe to grind against corporations with dark patterns
* chromebooks, where you have even less choice over the matter
* various flavors of Linux, which have never quite gotten to 'grandma uses it and it just works with the apps she likes'
Interestingly SteamOS is quite nice, but will it be something outside of gaming on a Steam Deck?
Considering their website[1] still says it's Debian derived but they switched to Arch some time ago, I doubt it's in their plans to do more than enable their own hardware.
Its impossible to compete when the manufacturers are actively hostile and don't provide the firmware/code/specs in a way that the hardware can be supported independently. Some even use this to spy under an umbrella of plausible deniability, there was an article just recently about Qualcomm chips that did this (checked in) at the firmware level.