The complaints that Kubernetes is "complex" are obviously comparing it to more targeted solutions and ignoring the aggregate system that arises in its place.

If you find a tool with a better fit to the problem, then yay for you do the smart and simple thing. In practice, though, for many shops there's a major hodge-podge of almost-there solutions which require much more specialization on much less popular frameworks with much less vendor support to compete with Kubernetes.

Kubernetes did not come into a vacuum: it's disrupted some mature solution ecosystems by being much, much, better.