I'll let Dan Walsh explain it https://www.redhat.com/sysadmin/rootless-podman-nfs
In short, you don't remap when running as root in the container, thus no uid/gid remapping.
I had a derp-out moment yesterday, I totally misinterpreted “as root in the container”. The topic was about rootless containers, so I was completely mentally blacklisting the idea of starting a container from the root user account.
> but that will actually work just fine if you stay as root inside the container, which maps to your uid outside the container