Can you speak more precisely about what costs you think something like k3s imposes that are solved by swarm?

Right now this comment has the same kind of FUD that I see in the swarm docs (there is no "why" to swarm in the docker published docs that feels particularly compelling, especially given the amount of time and energy docker seems to be putting into their k8s tooling instead).

I'm willing to bite - but I run a baremetal cluster on k3s, and it's very simple to keep up to date.

Not the parent but I had a Kubernetes setup I migrated to Swarm a few years back. I don't remember a most details honestly, but I do remember deleting so much configuration (and duplicate config with my local compose), and generally finding it much easier to work with. I even had a couple machines set up without much trouble as it was all built-in. But I'm not an infra person and my k8s experience is minimal.