Trading courses and coaches are useless- true or not

Why do successful traders not advise others to trade?

What books did you guys read when you created your own trading system?

How to solve the conversion between large cycle and small cycle?

What are the common operating modes of thousands of trading studios, and how do they support themselves?

I partnered with a friend to do asset management for a year, and then it all collapsed. Is there any colleague to share with you? I also want to try again, before I try, I would like to ask everyone's suggestions and experiences

Winning ratio and profit-loss ratio, which one do you value more?