Something often underappreciated is that, in the possible future you're describing, you can use all of these new fangled "what's old is new again" approaches by continuing to just use Kubernetes. Kubernetes is, in a way, designed to replace itself.

Kubernetes is software. It cannot do anything "itself" let alone "replace itself". Don't anthropomorphize software

Inevitably it will be a human replacing it with what they define is the best method