It is not possible to earn constant income from gambling. It is never possible to have a constant profit in gambling, because if there is a profit in a few bets, there will be a possibility of loss later. In this case, there is no continuous income, so you must take alternative measures in your career where you can get a fixed amount of salary every month. To this day it is not clear to me whether any profession or career has been formed based on gambling. However, if you want to build a career in agriculture, business, workshop, etc., it is possible to build a career, but it is never possible to build a career in gambling.
Gamblers who do this don't actually depend on the money that can be made through their daily gambling activities. During my few months research on professional gamblers I realized that they actually sponsor with their money. And focus on other beneficiaries from the casino to reduce their expenses. However, gamblers who don't have much money, but want to become a career gambler need to avoid it. Because there is not such way of making steady income in gambling. Retirees who want to enjoy their time off the cooperate world, could decide to do it via gambling for an extensive period of time. Thereby getting fun, and Aswell earning some bonuses from the casino. All this may not happen if the gambler is not keen to have some free time away from gambling. I mean the career gamblers still know when to stop gambling and take some rest.