The online casinos which are licensed in reputable jurisdictions, are audited and use good software are fair. By the way, the only “game” where casinos do set the payout percentages is slots. In land based casinos they can legally go as low as 75% but the competition for the gamblers bucks has driven that percentage up. The market regulates that stuff.
Generally, I believe that gamblers have an eye on all this rational information that my help them to minimise losses but at the end of the day a lot of them will act instinctively. Gambling like an accountant just doesn´t provide the most entertainment value. :Partier: