I use both (and others) for different reasons. However, the primary homelab server I use is based on Debian - Proxmox OS. It runs on the machine hardware you have but then you can run a few 'fake' computers (virtual machines) on top of that host OS. This is called a hypervisor. So when running Proxmox on the host, you could run a Virtual machine (guest) that is running Rocky and play around with that. Or Fedora, or Gentoo.. or ^A^r^c^h. That really would be the avenue to go to learn about different Distros and nuances without having to breakdown and rebuild everything every time.

My experience is that both Debian and Rocky are stable and very useful for what you need them to do. Debian favors stability, whereas Rocky favors being a RHEL compatible OS. It's easier to do somethings on Debian, but you may learn more enterprise aspects using Rocky.