Not to mention the default main branch of a git repo is master

Unlike the 'master'/'maintainer' role, the main branch does not directly correspond to a person.

A master/slave DB isn't a person either and look where that ended up.

Which no doubt comes from the term "master copy", which has a long established, and quite precise meaning. Choosing a different meaning arbitrarily(or actually, quite deliberately) is disingenuous at best.

Hg sensibly calls the default branch `default`.

Git sensibly calls the master branch `master`.

That's funny, because it's pretty common to set a 'dev' branch to default and reserve the master branch for production code.

We won't change that until git does. Of course you can customize your default branch.

Where is the slave

Try "main"

GitLab is about removing the needless ceremony to getting your application deployed.

Calling someone master can deeply offend. Are we really at the point where we cannot distinguish between a human being and an incorporeal blob of computer code? Life is going to be really, unnecessarily challenging if you go through it bending over backwards to invent new ways to become upset.