This is bad-faith AI slop rephrasing the original article, but regardless: the extent of the issue is far, far, far beyond the metadata you're discussing. No one has 300MB of commit messages.
Commit messages in https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin... sum to 900MB.
Also, this commit message alone: https://gitlab.com/old-game/sb-b/nanobox.io/nanobox-pkgsrc-l... weighs 100.5MB (they squashed years of history as a single commit and piped "git log" to the commit message).