What else am I missing?
The fact that 90% of people don't give a shit about ads, privacy or their operating system in general. They want a machine to open a browser, that's it. If Windows comes pre-installed, they'll use Windows.
The only realistic chance we've got is that MS shoots itself in the foot once more by all that Recall crap and businesses drop Windows. But that's a long shot.
... And then something happens and they want you to install Windows again.
As much as I like Linux, compared to Windows and Mac OS it's high maintenance. Once in a while, things will bork themselves. And you need to have at least a rough understanding of what's happening to fix it.
Also (and that's not a Linux problem per se) people seem to think if Windows breaks, MS or they themselves are at fault, if Linux breaks, that weird nerd and his hacker stuff are at fault.