IMO the best use of git for Nostr events is for long-form content. Being able to, for instance, do version control on a full publication before it is broken down into 30040 and 30041 events and pushed off to relays could have a use case.
Smaller content, such as text notes or comments, are generally one-shot and don't really need versioning.
That said, git could be useful if one wanted to do version control on a local archive copy of one's Nostr profile and associated events. Dump everything into .jsonl files, perhaps.