Didn't read any of the inapplicable nonsense that followed the inappropriate insertion of forum defined.AZBilliards encourages discussion and will allow even questions AZers can't answer. Many AZers are anonymous and could include Thomas Haas and Joao.
I'm guessing there is little money for players in Haas-Joao-like games except from gambling.
Viewing the Haas v Joao match on YouTube that lasted over three hours was underwhelming. There must have been a scorekeeper but was there even a referee? I didn't notice an audience and no one there likely paid an admission fee. I doubt YouTube paid them much if anything. I doubt Haas and Joao got money from a sponsor.
Gambling is a problem in sports but it is even more of a problem if players rely on it to get paid.
You asked where they get their money.