Bro trading can never be a one man profession, because trading is an uncertain thing. There is no guarantee that you will always profit from this (no matter how big a professional trader you are). Just as big profits can be made from trading, there are sometimes big losses too. And to compensate for that later, you have to suffer a lot. So trading should never be chosen as a career. But yes, you can do trading if you have a fixed income every month.
You sound like you are referring to gambling because that is not how trading is. Why can one not choose trading as a career if they have the skills and knowledge for it? Trading is not solely based on luck, it's gambling where you need the luck to be on your side for you to make money, but when it comes to trading, if you understand the market and know all the tactics and strategies and ways of the market, you can earn money from it without a doubt.
I know a lot of people who are professional traders, they earn a living through trading, and believe me, they are doing much better than a lot of people who are working at high-paying jobs and utter bad words for online businesses, cryptocurrencies and all other stuff related to them.