I could be wrong, last time I seriously used MacOS (for both personal/work uses) was Mojave. Either way, it's installing a lot more than just the 30mb of the git binary, so I learned my lesson and just installed all the GNU stuff with my package manager. Annoying to be sure, but somehow better than dealing with Apple's default way of handling it.
Mandatory reboot? I've never experienced that with the Xcode command line tools.