I think you are right. Tarballs with version strings as filenames served from an HTTPD are effectively a poor man's version control. Git commits are immutable and efficient (storing only the delta) for text, but those same benefits could apply to binary files too if only the tooling was better. You may be interested to know that Debian actually does use Git to store binary data, although only when it is not possible to use the source files to generate the binary data directly.