~/.mozilla/firefox/<profile> is a mish-mash of data, config, and cache. It's not simple to unravel that.
Beyond that, it would be a breaking change, and that requires more caution.
This is one of the reasons I use Flatpak whenever I can. I've revoked all Flatpak apps the permission to access the root of my home directory via a global override, so anything they wanted to do in there (e. g. create folders, place malicious code in my ~/.bashrc, etc.), actually happens in ~/.var/app//.