Up Grade to SemiPro or Pro

Investigating a bit I see several Recreationals that become pros with an abysmal growth with the initial stack. My question, what does it take to get to that level? Does being pro or semi-pro depend on playing time or is there some strength to exploit?

I think you still need to thoroughly study the theory from the beginning. And in the future, you need a lot of gaming experience, there is no professional without experience. Experience is needed to test the theoretical knowledge gained and choose the optimal game for yourself.