I had to update a Chromebook-like machine that was running Windows not to long ago. It was excruciating. The restart progress bar on one update after reboot took ~30 minutes to reach 3%.

Keep in mind that the computer is unusable during this time, and all it takes is one poweroff to brick the machine. Ask me how I know :) . I had to leave it plugged in overnight to finish.

If this comment is referring to Windows reboots after update, I will call it confidently incorrect.