Whats so difficult about k8s? Kubernetes and especially the managed versions allow you to be a simple or complex as you want to be. What's the difficult part?

This is valid criticism. It's leading to an interesting rift or tension, at least at my current workplace: Infrastructure like this enables teams to be agile, but the infrastructure itself rapidly stops being agile and you need to have a 1-2 year planning horizon.

A good platform enables you to deploy several times a day (if you want, you can always choose to go slower). But changing a core infrastructure piece if dozens of teams and dozens of dozens of service deployments depends on it... a year is suddenly a rather short time. In fact, I'd say you're not replacing such a core piece, you're rather adding a new deployment infrastructure and now you have 2 for a long time.

As such, going for all the bells and whistles you might need 2-3 years down the road can be a very valid point - as long as you have evidence and reason to believe the complexity will be utilized.

Otherwise, I'm totally a friend of having some Jenkins Job or Github action to rsync jar-files to from Artifactory to servers. Standardize the App-Server and the 1-2 java versions to have, have a proper systemd unit for it and have at it. We've run the company software like that for years. It just wouldn't work at the current scale.

But what about if the server disappears or the disk failed and it won't start? It doesn't capture the entire process.

I remember at some point we needed to deploy to a new region for a customer and yes it was "too difficult" because some of those manual steps were forgotten and lost. In became a x month long effort to work out all the small details.