There are some online courses that can really help you get in track but they're a rare gem online as the most popular online courses are just clickbait or just a quick cash grab for the creators of those courses, you're right that it's all theories but at the same time we also need to do some applications on those theories.
That's where they make money most.
From the sales of those courses that they make and they're earning from thousands to millions there instead of actual trading. They know how to sell and they know the basics about trading.
But there are those pure that just want to share their knowledge.