Having set up couple of clusters myself, professionally, I can say setup is extremely easy relative to the functionality you are getting if you wanted to get it by traditional means (traditional = pre-cloud tech).

What is complicated is that this absolutely does not absolve you from having to understand everything that is happening under the hood. If you feel Kubernetes replaces that requirement you are doomed first time a non-trivial issue happens.

Could you share some insights on what you think is "extremely non trivial"? In what way is Kubernetes harder than what's to be expected of a technology that orchestrates serverside software? Doesn't this rather depend on the actual services you want to run rather than Kubernetes itself? Obviously it won't reduce complexity of what you want to run, but it makes deployments of it pretty straight forward as far as I can tell.