It is meaningfully different because, as the article says, comments are known to not be machine verified and thus to potentially be wrong. With type hints, the

It is meaningfully different because, as the article says, comments are known to not be machine verified and thus to potentially be wrong. With type hints, they’re usually verified, but not always, so you’re more likely to trust them and get a nasty surprise when they turn out to be wrong. However, there are other aspects to the article’s argument, such as the fact that it’s easy to end up with type annotations going silently unenforced even if you do run the checker.