kubeadm is not fixing the underlying complexity - it's putting a veneer on top. It's certainly helpful to simplify the deployment, but kubeadm is only needed in the first place because of how complicatd kubernetes is.
To be clear I'm not saying there aren't deployments where the complexity of something like kubernetes isn't necessary.
But most people only run a small number of servers. I'd argue most clusters people are deploying are going to stay below 10 servers for their entire lifetime, and a dozen or two services that generally tends to need basic high availability and load balancing and 1-3 different data stores with replication/data persistence requirements. For that kind of setup, while you certainly can run kubernetes, the complexity of it simply isn't needed.
That's the boat I'm I'm - we have less than a dozen services and all we need is packing them neatly on worker nodes and some load balancing. Setting up Kubernetes for that looked like an absolute overkill. I need to try Docker Swarm and Nomad again but either of them has to support rolling deploys out of the box - lasy time o checked neither of them did
To be clear I'm not saying there aren't deployments where the complexity of something like kubernetes isn't necessary.
But most people only run a small number of servers. I'd argue most clusters people are deploying are going to stay below 10 servers for their entire lifetime, and a dozen or two services that generally tends to need basic high availability and load balancing and 1-3 different data stores with replication/data persistence requirements. For that kind of setup, while you certainly can run kubernetes, the complexity of it simply isn't needed.