Grabbing git repos instead of just tarballs is useful.
A) You can update them, because you can git pull to fetch changes.
B) If you want to apply patches on top, its better to have version control so you can keep track of what you changed, especially useful if you want to rebase.
A) only valid if you want to stay with the devel version
B) See A
I use OpenBSD and before that, I was on alpine, debian, and arch. Of it was a software I want to try, I downloaded the tarball. if it’s something I wanted to keep for longer, I created a port or a custom packages.