Windows is fine at being an OS, most of the time it just works. I think the exact same thing is true of certain Linux distros, especially for the average user who could load it up, browse the internet and watch videos without ever breaking or having to debug anything.
If we're purely talking about the OS. Forget software or imagine you're exclusively using software that works fine on both. I think Linux is a much nicer experience. It has really improved over the years.
Obviously we can't just ignore software, though, and that's a huge part of why Windows is still so popular. But another huge part is that Microsoft pays a lot of money to make it the default OS on lots of hardware. I can't even think of a single person I know who chose windows, it's just what companies use and what most computers come with pre-installed. Companies like it because Microsoft provide tech support. There are many reasons why Windows is so popular that have nothing to do with the user experience.
Sorta but not really, it's ubiquitous now so it almost has to be on new hardware, and Microsoft offers big discounts for OEM versions. They lose money to guarantee it stays the default I guess? Either way, I still don't think there's a lot of people actively choosing it.