There are essentially no real barriers to entry in trading. If the strategy is simple, it has been arbitraged away by the pursuit of millions of traders before you. That is simple logic.
"Some guy crashed the entire global markets with a very "simple" strategy." Who? Navinder Singh Sarao? He was convicted. Hardly an example of a succesful trader with a simple strategy.
Ah, ok, you're right. I have no idea why I undermine myself like this. My generosity gets the best of me, I guess.
Only complex strategies work.