@Duplucky I don't know where you've read/heard that, but it's quite easy to verify. Just open any book or article in English and check how the punctuation marks are done. There is no need to become crazy about such a simple rule.
@Sentinelle How do you know that? I've a Bachelor in English literature and I would be unable to say with certainty what were common mistakes among my fellow students
The only thing I know is that Word or Grammarly, by default, consider the space before the punctuation mark as a mistake, and both highlight it. Since most students (afaik) write their essays with those, I would assume this mistake has become pretty unusual by now.