The typical reason is that one has a build chain which predates docker and those things, where it wasn't guaranteed that doing it on different machines yields the same result, but having a master host gives consistent result, independent from who does it.

In modern times the reason is that the release is produced in a CI pipeline. So once a build is green and matches allmothe rreleas criteria that tested build is released.

In both cases using a git checkout for longer time is not a got idea and builds should be done as exports into clean directories.