As a VC-funded company Docker had to make money somehow.

I recommend using GitHub's registry, ghcr.io, with GitHub Actions.

I invested just 20 minutes to setup a .yaml workflow that builds and pushes an image to my private registry on ghcr.io, and 5 minutes to allow my server to pull images from it.

It's a very practical setup.

I think the complexity lies in the dance required to push blobs to the registry. I've built an OCI-compliant pull-only registry before and it wasn't that complicated.