My experience is that many changes span several blocks of code in a repo, so there's not always one single location to put the comment. There's also a blessing

My experience is that many changes span several blocks of code in a repo, so there's not always one single location to put the comment. There's also a blessing in that git commits don't need to be maintained like comments. Comments can drift if not maintained. A commit is only observed in-context. Most developers seem to be poor "commit historians" by default, I'll admit. If you have the energy and consistency to enforce good history, it eventually becomes self-sustaining.