I’ve only ever corrected anyone once, and that was on a totally different, largely male forum, when someone had corrected someone else - and made a basic mistake in his own post! (I enjoyed that! ?)
The most cringe-making example I ever saw, though, was on a writers’ forum, when someone used a Latin phrase wrongly, and someone with a high opinion of herself, undertook to correct her on the open forum. It wasn’t a public forum - many of us knew each other - and she could easily have sent a PM, but chose to humiliate her instead.