Only if you actually has a system complex enough to require it. A lot of systems that use kubernetes are not complex enough to require it, but use it anyway. In that case kubernetes does indeed add unnecessary complexity.

Except that k8s doesn't solve the problem of generalized distributed computing at all. (For that you need distributed fault-tolerant state handling which k8s doesn't do.)

K8s solves only one problem - the problem of organizational structure scaling. For example, when your Ops team and your Dev team have different product deadlines and different budgets. At this point you will need the insanity of k8s.