i agree but also taking risks sometimes will pay you well, although i also say you should research and know the owner first and see how serious they are about their site.
casinos like primedice, crypto-games,... were some day new too. and now they are big. so if you could find one of those in early days when nobody invests you will be a big share holder.
Right, casino investments are not buying shares from that casino, but investors are helping to maintain high bankroll for the casino so casinos will pay some % of the money they earned from each bet. But should invest only in already trusted sites to reduce the risk of losing all your money.