If you want to invest on casinos, pick one with a good bankroll management (for example, crypto-games) because there are times that a high roller would win x consecutive times and you will surely lose your investment in no time.
There are several problems which maybe you are not aware of mate and hence let me help you out. The first and actually the biggest danger is that the site we invest might turn scam anytime.
Secondly, there is only a house edge of 1-2% and chances are there gambler wins too. Thirdly and might be wrong, I wonder what stops site from claiming their own wins as players, I mean they pretend to be players and since they know the seed win the bets ?