I've found several threads like what you asked about and it seems that there are lots of opinions conveyed by members of this forum and different of course.
If I personally have the opinion that there are indeed some gamblers who have succeeded in making betting or gambling a place where they can get a source of income or make a living, but not many and not all gamblers can do this.
Betting is an activity that has a very large risk so that it can make a person lose all the money he has.
I'm sure those who can use sports betting as a source of income are gamblers who have been betting for a long time and they can have a very good way or research to be able to predict a win so they can bet correctly.