If you have knowledge of the subject matter, then it's easy to see if an author knows what they are talking about, but if you are a beginner, it is fairly common on the internet to have articles, tutorials, and videos, where the author just learned the subject themselves and are now repeating the information they themselves don't fully understand, and are accidentally mixing in wrong information with the correct information. The beginners can't detect it, so they believe the good and the bad.I think if you read the article closely it's fairly easy to tell if the author knows what they are talking about. Beginners tend to gloss over intricate details and focus on the basics, where experts tend to focus on the intricate details and skip over the basics.
Peer-review is important, but should an article that is 90% correct be rejected because it is 10% wrong? On the other hand, should the 10% wrong be allowed to continue to exist while waiting for the original author to fix it? The peer-reviewers should be able to edit articles, and the original author and other peer-reviewers should be able to see the history of edits, and the author should be informed of the edit. Even easy-to-make mistakes might misinform a beginner for years to come, and the sooner those mistakes are caught, the better.