Is it real that people make money from affiliate marketing? Yes.

Is the stuff you're learning from useful or real? No clue.

Is it worth spending the time to learn and implement stuff? Depends entirely on what you define as worth it or not.

Side note: HN isn't really the targeted audience you're looking to get advice from when it comes to affiliate marketing. While there are some affiliates on here, you'll be better off targeting affiliate communities for your questions.