I don't think I've actively used a Windows computer in 16 years for much beyond VR, but, I don't think I've seen a force-installed upgrade since XP. Is this really a thing?
With partial countermeasures, like disabling the Windows Update service, several other services (Windows Update Medic (WaasMedic) and Update Orchestrator (usosvc)) and scheduled tasks will do a variety of things silently to make WU active again. It may try to update at strange times after making those repairs. Sometimes, it grabs new firmware for OEM laptops and installs that during the reboot. That's not comforting in the slightest.
If you delete all the associated scheduled tasks and manually disable all of those services, you can get a few months, maybe a year or five of uptime.
A lot of the preferences of Windows 10 that people hate, (ads, extra telemetry, cortana etc) aren't even defaults, the system explicitly asks you when you install it. But if you only know Windows 10 from pre-installed prebuilt computers, manufacturers make those choices for you.
Updates are officially required. [2]
Each release makes it more difficult to positively force WU to fail with user-facing tools. So now, in 2022, after 13 major releases with different UIs, waasmedic logic, and policy effects, when I need to keep a computer online, I don't consider the options that I've found to have failed before (where failure is equal to rebooting). I kill the components of WU, repairs to WU, and repairs to the tools that repair WU.
As a result, or as a consequence, you decide, I usually don't get updates again for a long while.
[1] https://social.technet.microsoft.com/Forums/windows/en-US/30...
[2] https://en.wikipedia.org/wiki/Windows_10#Updates_and_support