When you have nextcloud, immich, vaultwarden and navidrome, this is real data that you're talking about on services that I use several times a day. I had an overnight blackout that took me a few hours to recover from. No data lost and have a 3-2-1 backup system but that takes time and energy to fully recover from.

After that, bought the cheapest UPS I could find, installed NUTS and not had issues since. Most blackouts seem to happen overnight and all have been less than 5 minutes.

Buying a UPS that would last for 12 hours minimum (happens just after I go to sleep and I realise in the morning or happens at work and not back home until then) is much more expensive and difficult than installing CUPS to have it switch off. Then I can wake up, turn the machine back on, wait a few minutes and everything will be back up. I can run tests but if I need to go to work I can leave that to later and what works I can use.