Yeah it is a pity people think this way. If you create something that just works and don't need bugfixes for a year then you are punished! Probably those people should add empty commit "nothing to do!" and do release "release notes: nothing more to add or remove"
Docker Compose is still a moving project. Look at the version of the schema. It evolves.
Kubernetes is also a platform that is moving. And it is moving fast.
If Kompose was considered `done` by its authors in 2020, I don't think I would even bother trying it out. It probably wouldn't be able to parse recent Docker Compose schemas and it would probably output outdated Kubernetes manifests.
But, see, yesterday I was looking for a Time Boxing application and stumbled on that one: https://github.com/khrykin/StrategrDesktop/. I dismissed it because the last release was in 2020. But that is an example of an app that could be considered `done` and still useful 3 years later.