Every single gambler knows that in the long run they are in red yet they keep playing in hopes that they will get that big of a win,it is that that keeps gamblers coming back even when they go bust in a big way by losing a lot of money otherwise they would stop gambling very quickly.No one can make 100 dollars every single day in a casino as this is plain impossible but everybody keeps coming back there to try their luck in a new day and this is what keeps casinos happy as they get money in every day because from 100% of gamblers playing there only 5-10% win something while 90% go bust most of the time.
The only chance someone can make 100 dollars daily is if they play skill games like texas holdem poker or sport betting where 50% of skill is still involved.
You are right, I would say that those who can win really well are even less, maybe it is 1-3%, and the minority is winnings in the casino, and a little more is gambling. Players return to recoup, or for adrenaline if it's just a game in order to distract from work or from the daily routine. I also believe that winning $100 a day is impossible, and if you believe in it, then just try playing for a few months and see for yourself the result.