Fedora/CentOS bootc relationship with Fedora CoreOS

By far the biggest difference between the two is that Fedora/CentOS bootc emphasizes users deriving from our container base image, making arbitrary, potentially large changes. Up to and including custom images.

Fedora CoreOS (much like Fedora Atomic Desktops) generally emphasizes users configuring an image pre-built by Fedora, running workloads as containers in general, but also supporting changing config files and kernel arguments.

A good example of the division line is Fedora CoreOS system extensions aka "package layering".

If you find the need to make such changes to the host, then you may find Fedora/CentOS bootc a better target.