The courses are usually worthless money grabs. A lot of these so called expert traders have been called out on their scammy tactics of selling "courses". Some of them have even received cease and desists and sometimes entire lawsuits have been thrown at them for financial advice that lost people a lot of money. That just goes to show you can't trust youtubers and influencers.... And just because they say "this is not financial advice" in their videos, does not make it actually not financial advice....
Some people learn the hard way.
If we wanted to become successful, then we have to consider trading as a serious job. We can really found a lot of trading tutorials online but we can't just rely on them but rather involve ourselves in real trading as this will teach us a lot in returns.