First, only anyone can edit other people’s comments; only repository admins can edit messages in the repository. Also, anecdotally, it is overwhelmingly positive to me, only harmful in extremely limited number of cases (this be one of them). Many people don’t know how to use Markdown (probably don’t bother to learn) and produce gibberish issue reports. Those would have been difficult to manage if edit were not allowed. Sure, it is possible to do without edit, but it’s the same the other way around (GitHub does keep edit history).

Github may keep edit history, but it seems like maintainers have the ability to remove previous edits of comments entirely, as is the case in the linked PR (perhaps it's limited to Enterprise?)

I don't like this. A maintainer can fake another users' comments for some very nefarious purposes.

Yeah, it's an optimistic biased system, but it's a decent practical approach. The cases of maintainers being lousy seems pretty uncommon.

AFAIK the reason maintainers can completely remove revisions of comments, is because occasionally a well intentioned user pastes sensitive info into a comment and doesn't realise.

While pointing it out to the user so they can remove it themselves does work, that's an unbounded time frame (perhaps never). So just nuking it directly is "safer" in that instance.

Doesn't seem like there's any really perfect solution.

I know our team commonly uses it to edit canonical issues over time. It’s much easier to follow a long issue if you keep the latest information in the original text.

Also github has a lot of use outside of public repositories. If I’m not the admin of my own issue tracker, I’d switch to one where I am.