This is absolutely correct If the markets were efficient and equivalent to random brownian motion, Jim Simons wouldn't be producing 50%+ returns for decades no

This is absolutely correct If the markets were efficient and equivalent to random brownian motion, Jim Simons wouldn't be producing 50%+ returns for decades non-stop in HFT. His net worth is 25 billion dollars, and there are other countless billionaires, made from the "efficient" markets. That's how much this fallacy is worth.