Whatever technology you use, it doesn't dispense you from monitoring and making it resilient. K8s isn't different from anything else in that regard.
With single server, complexity is much much lower. I installed my server years ago, once a month I check logs and do updates (10 minutes of work). Some time next year I will upgrade to Ubuntu 24.04 and replace SSD (just in case), about 1 hour of work.
K8s is really horrible when it comes to time efficiency!