Been dual booting for >20 years now. It's nice that some games work on Linux pretty well these days, and of course I had fun messing with Wine manually to get some stuff to work decades ago. But it really doesn't bother me too much to reboot when switching between gaming and literally anything else.
Apparently you can get a mobo with switchable BIOS config (or was it just a switchable SSD?) so the OS didn't even know that there's a second OS around. If there's no connection of the other OS then MS can't break it [as easily]!
IMO it must be malicious, because otherwise it would be caught with remedial testing. I can't believe MS don't include dual boot setups in their testing.
The functionality is present on my new Lenovo laptop, various generations of HP elite/pro books/desks, old asus mobo and newer cheap gigabyte mobo, 7th gen intel nuc.
This description doesn't really do it justice. ~75% of top 100 games work well out of the box/with minimal tinkering according to https://www.protondb.com/dashboard (it varies a bit based on the rating scale)
Many work perfectly and many work even better than they do on Windows. Valve's work really changed the game over the past few years.
oh man, do I have some really bad news for you: