I have had one up for around 2 years now and would say I have spent less than 5 minutes maintaining it over that time period. I did spend more than typical time setting it up because I added a custom php page so I could remotely add client ip addresses to the dns iptables whitelist, but I could have just done the basic setup in <20 minutes. It’s solid as a rock. Am I lazy about it? Sure. But I don’t quite consider it critical. It’s just personal use basic internet. And if something were to go wrong, most if not all client configurations have a backup/secondary dns option anyway so as long as that is configured things keep working fine, just with ads.