Just think if someone is making a lot of money he will share his strategy with others if there isn't any benefit for him. A successful trader won't waste his time making videos to teach others if there aren't any benefits for him on that because trading requires a lot of time so if he gets any free time he will use that with his family or in something fun for a refreshment. Most of the youtube trading channel owner is content creator, not a trader. They earn by making content not by doing trading so the strategy they share is not tested in the real market. They just made those to impress his audiencee.