Is there a commonly accepted reason why Microsoft makes these big releases so different?
AFAIK macOS has relatively minor changes, in terms of UI/UX, from release to release (look at screenshots of the original OS X vs. the current macOS version). And Linux is entirely dependent on distro, but for me it’s just “has i3wm changed drastically? No? Great!”
My guess is that Windows just does it because they need folks to upgrade, and that’s the only tool they have to force people’s hands…