Here's how it works. By law, all machines will require networking, or will refuse to boot.
Network stacks will require a key / license. Licence will be verified by an online server, continually, and any OS without this will be fined, and the devs implementing a bypass jailed.
Stop complaining/pointing out flaws, or you must hate children! Or... are you one of them?
Microsoft are slowly baking in this concept into Windows 10/11 to become more like an XBox at least for the home version. I envision a future version of windows will operate very closely to the method you described. I suspect all of the OS vendors want an app store in front of everyone whenever possible and telemetry to see what needs tuning to keep interaction with the app store as high as attainable. I do not believe it would be a stretch to see a future home version of windows not allow login if their authentication servers can not be reached or if ones cached remote credentials expire.
I could even see this eventually happening with Linux. The latest version of the Fedora desktop F36 interacts heavily with admin.fedoraproject.org and they have an app store. AFAIK Redhat/IBM have not yet implemented any centralized authentication servers with corresponding default client configurations to utilize them and I do not know if they intend to.
The desktop OSes are heading there too but they're still a bit afraid of pissing off their legacy users. Besides the lock-in they're all aiming at that sweet 30% app store commission.
I disagree. It might happen to some flavors of Linux like Fedora, Ubuntu and others that are backed by companies. But because the source is open, there will always be distributions that do not have such a restriction.
In addition the EU is also working on an online ID so a website can request your real identity and verify it. This would link in with that, validate the user as well as their hardware.
Right now? No. But I could see it happen in 10 years. Especially once CSAM is no longer the scapegoat and they have admitted they want the data for a lot more surveillance. I can already see the posts of people that think they have nothing to hide.