Don't get me wrong. I detest what Microsoft did with Windows 10 to strongarm their way on the customer and take telemetry data. Between that and running unpatched - however - putting up with Microsofts Win10 shit is by far the lesser evil.
Personally I have given up on Windows completely for my general purpose computing. I keep it around solely for games, and do everything else dual booted to Windows.
I see what you are saying about only using it for games limiting the likelihood of exposure, but is that entirely honest? Are there never times when when one Google's for game patch notes, troubleshooting during crashes or anything like that?
Is it really worth becoming part of a botnet, acquiring a keylogger, and potentially having an expensive Steam account stolen? Or even worse, having all the partitions on your local machine ransomwared?
No offense, but you remind me of a person whose life is wrapped up into the one thing they do, like making a special kind of rubber for some shoes that is 371% more efficient than other shoe rubber and absorbs 59% more impact than another shoe's rubber, and so everything for that person comes back to the topic of shoe rubber and how this one special kind of shoe rubber reigns supreme over all others and if anything bad happens it has to do with how that special shoe rubber wasn't used.
The point of having a computer is to be able to do the things that you need and want to with it. Usability naturally comes before security, as without something usable there is no need for security to protect it. Therefore, when Microsoft's tyrannical updates regime threatens the usability of a system, the thing of primary importance, its usability, must be protected by shutting off those invading updates.
Security is dependent upon there first being usability, and so usability is a greater consideration than security and security is secondary to usability.
Any disruption, hoop-jumping, or delay to being able to do what a person needs and wants to on their computer is a problem.
A person decides whether they want Microsoft to be harvesting personal and other data from their computer. And if they don't want Microsoft harvesting data from their computer, then Microsoft harvesting data from their computer without willed permission is a security risk.
Windows Updates breaking things and bricking systems is a security failure.
As has been stated, Windows Updates patches do not equate security, and are even large security risks. And letting Microsoft have free reign to do whatever they want to your PC and OS is a massive security hole.
By arguing that people should have no control over their system is like stealing people's rights over their own property from them, and is advocating for Microsoft's reign of tyranny.