As far as I can see, Its not hard to make it as a Gambling streamer - once you get the sponsorship that is.
DO
1. ...
And most importantly:
0. Make gambling look fun. You are an advertisement for gambling, you need to look the part or they will stop paying you.
This can be difficult since slots/C&T games are really boring to play for hours at a time. To make content more interesting, the most successful gambling streamers will make games out of it, like going on "bonus hunts" where they close the tab every time a slot hits a feature, then open them all at once (80-120+ slots) during peak hours and change their stream title to get lots of viewers. Some channels like ClassyBeef or Casinosquad_XXX (where XXX is ITA, ENG, or some language) have dedicated teams of streamers all on the same channel who work in shifts to stream slots for longer hours without melting their individual brains. Other channels still, like syztmz, make games out of it: he has an entire website where users bet on what slot machines played on stream will do well using in-website points and compete on leaderboards.
The quiet part is that going on massive "bonus hunts" or pitting slot machines against each other in tournaments with 100+ dollar buys is way out of reach for the average unsponsored gambler. The point of these streams, like most advertisements, is to develop a familiarity bias in the viewer with the casino and its products. When a sponsored streamer with a million dollar balance like trainwreckstv loses a lot of $1000+ spins in a row and claims he's showing off the reality of gambling, he's missing something that we see in bossmanjack. That is the fact that having a low balance, like $20 doesn't usually get you very far. Hacksaw slots (think: Densho, Rip City, and friends) can look fun in a bonus hunt with a huge balance, but they look bleak and depressing when doing .20 cent spins on a 20 dollar balance and losing everything.
Bossmanjack makes gambling look like hell, which is why I think he won't get any non-sketchy sponsorships. I know that gambling would be a bad idea for me, but watching these streams gives me a newfound confidence that if I played the same games as him, I too would hate my life.