That's why people invented sharpe ratios. They allow strategy comparison. Find anyone who thinks they can predict the market and get them to reveal their sharpe ratio.
I only discovered these grey/green-themed Youtube vids recently. (Within the last 6 months??) And usually, such well-polished/produced things are utter buffoonery that borders on criminal fraud. But I've seen at least a dozen of these things -- if not more -- and if that's only 10% of "106 episodes".... they've all been pretty sound.
That’s the podcast I mentioned earlier. He doesn’t go too in depth on strategies as his old business is still trading but still interesting.
You know hft is similar to old school arbitrage. Eventually technology will catch up and it'll disappear or the risk/benefit is so minute it's not worth the effort. By the time you raise enough capital to give it a go, there will be something new. You may lose your capital trying. IMHO it is better learning to be profitable within the market rules and regulations.