I had a bad experience once where after a bigger update a Win 10 laptop absolutely refused to recognize the touchpad. I had to revert it to basic mode in the BIOS settings, meaning it was usable again to point and click but I could no longer scroll with two fingers and the like. Very annoying if you take it over to the couch without an external mouse and keep trying to scroll and nothing happens.
I spent about two hours trying to fix this and once again cursed the fact that laptop manufacturers put hardware from multiple different companies in one and the same model of laptop and it's up to you to figure out which bluetooth radio, WiFi card or touchpad exactly is in the device in front of you. It still doesn't work to this day. Curiously, I know a second person who owns that exact same laptop, and their updates ran without any touchpad issues

I'm also still puzzled by a UX choice such as this:

What happens if I click that Restart now button? Am I going to break my system? I kind of doubt it but I'm also afraid of trying it.
Something like that should never happen.
And there's still a horrible translation error in the German version of the Update settings, where an on/off option label about restarting the device as soon as possible after a bigger update reads like a request by windows instead. ("Restart the device ..." -> "Starten Sie das Gerät [...] neu ...")
It also looks like when you shutdown your computer in the middle of an update, Windows goes into hibernation instead. This makes sense obviously, but it's not actively communicated in any way.
Long story short: I get people's skepticism about Windows updates. Should you still keep Windows up-to-date? Yes. Should you keep around an old laptop or tablet in case the update fails and your system goes tits up? Also yes.