Honestly I should. Registry and stuff gets cluttered. Programs don't uninstall cleanly, or they change settings I can't find. On one machine I somehow set it up as a wifi print server or something and for the life of me couldn't find a way to turn it off. But it's such a hassle to setup a computer.
Cluttered registry does not impact performance.
Unclean uninstalled programs also don't impact performance. Unless it really isn't uninstalled and still runs in the background, but that can easily be fixed by a person competent enough to reinstall Windows once a year.
Settings you don't find, will still be not found after reinstalling Windows.
But to each their own...
What are the practical issues with "cluttered" registry? But also, you can use special apps to track installations and do advanced uninstallations for ~clean uninstalls. Likewise, you could even spend time tracking settings. So yes, still a hassle, but nothing comparable to setting/reinstalling everything from scratch, that's just pure waste