I'm also constantly surprised at how unpopular docker swarm is given that everyone already uses docker itself. Why do you think swarm is going away though? I love the idea of just using my docker compose file as my deployment config.
I've recently started using Kompose to autogenerate Helm charts from docker compose files and I've found that pretty satisfactory.
That said, I was at a conference, talking with a CIO of a K8s related company, back during the initial days of that startup ecosystem. I was told off the record that Google and Redhat were offering an "marketing budget" for companies that would come on board the Kubernetes ecosystem. The person rightly stated that K8s was going to roll everyone else because of it.
Can't validate that - it's hearsay, but I definitely think that it was a big factor