I guess it takes years... and LOADS, yes literally loads of efforts and work. At least if you mean to make a smaller living from writing here.
Still, this depends on the person we are talking about and the amount of effort they are willing to make.
I think it is the best if you set a goal for yourself and try everything to achieve it here.
At this moment my goal is to write 50 hubs altogether (3 to go :)) and then to get involved in the apprenticeship program. I hope I will be able to achieve these goals.