Kubernetes is one of those things that are only as complicated as you want it to be.
The problem with Kubernetes and complexity is that because it simplifies a lot of things that are a huge PITA to accomplish on a "homemade" server/container setup is that there are a huge number of products and things you can run on kubernetes to "do stuff".
And it is hard for a lot of people and organizations to resist the "oh shiny" aspect. Stuff like "Oh, look I can do network policies and service meshes!" or "Lets create this really complicated and big thing so we can configure all our AWS infrastructure with kubernetes objects! Who cares that a bad commit can destroy the infrastructure the cluster depends on along with our ability to manage any of it!" or "Look we can have lots of namespaces for all our internal orgs and departments, lets make a gigantic centrally managed Kubernetes cluster that will be managed by IT and that everybody will be forced to use at the same time! Putting all our eggs in one basket is a awesome idea!".
K8s sorta removes the barrier of entry that world normally stop people from implementing those sorts of bad ideas.
Otherwise the core vanilla Kubernetes isn't really that complicated compared to most DIY solutions that try to manage large numbers of apps on clusters of systems. Most of the time it ends up a lot more robust and simpler in the right hands.
