Yes, it is possible!
1 - The owner of the casino lives thanks to the profits of the casino, that is, he lives thanks to gambling
2 - Casino employees also receive casino salary, they live thanks to gambling
3 - Professional bettors also live thanks to the profit they make from the bets they place
You can only put a lot of effort into studying a lot about sports betting to become a professional gambler, don't expect that you will consistently win money with games that depend on luck like slot and other gambling that depend on luck
I think the third point should be changed to "professional analysts" because if someone is so strong in analysis that he can make money on betting, then he will choose a stable job compared to betting where even with perfect analysis, a series of unforeseen results occur.
And in general, I doubt that now someone lives at the expense of betting, as bookmakers are constantly improving and if in the past it was possible to beat them stably, now it is extremely doubtful.