You've done well so far and you have created your own voice here - that's very important. You have a brand. Maybe you won't get to be among the highest earners on Steemit, but you can still be a good earner and write whatever you feel like. As for living off the earnings, I think that depends mostly on the crypto markets - I don't know if you'll ever get enough to buy a Lamborghini, but at some point we might get to the point where Steem will be high enough to cover everyday expenses.