That's quite interesting, although back in the day we did that for C dependencies that weren't packaged well, and it quickly ballooned the size of our repo since git has to treat tar balls as binaries. Even if you only update a few lines of the dependency for a patch version, you re-commit the entire 43 MB tarball (obviously that depends on the size of your tarball).
You could use Git LFS to store anything ending with a tarball extension. It's pretty well supported by most Git servers (I know GitHub and GitLab support it off the top of my head). You do need the LFS extension for Git to use it.
