Sorry, but that's just ton of FUD. We run both private cloud and (for a few customers) AWS. Of course you have more maintenance on on-prem, but typical k8s update is maybe a few hours of work, when you know what you are doing.
Also AWS is also, complex, also requires configuration and also generates alerts in the middle of the night.
Also AWS is also, complex, also requires configuration and also generates alerts in the middle of the night.
It's still a lot cheaper than managed service.