This doesn't agree with my experience. If the time were consistently off by multiple seconds then the sweep second hand on my apple watch would stutter whenever the time was re-synchronized, but it does not.
I only have access to Android devices, so my claim likely won't extend to Apple. In fact, I've been told by a friend that Apple watches do in fact use the GPS signal to sync the clock. But as far as I know, they are the only ones doing that.
I never made the claim that there were no solutions to the problems outlined above. In fact, I implemented exactly what you've linked long ago. This doesn't, of course, change the fact that no such easy procedure exists on unrooted Android devices and that Windows, by default, has inaccurate timekeeping. Requiring extensive configuration for something as simple as accurate time is what irks me. Time sync is neither expensive nor complicated, so why is Windows so reluctant to do it often enough to keep the time?
Having to set registry values to get sane syncing behavior is just nuts when, again, my cheap Casio watch - which possesses a miniscule fraction of the features of a modern computing device - can deliver sub 500ms accuracy with absolutely zero fuss.