UK online casinos operate under strict UK Gambling Commission rules that...

https://juliet-wiki.win/index.php/How_Do_Casinos_Pay_for_Game_Content_-_Flat_Fee_or_Revenue_Share%3F

UK online casinos operate under strict UK Gambling Commission rules that protect players and ensure fairness. Despite this, they find ways to stay profitable, like setting games with around a 96% RTP