Not really, there is Terms if Service in every singke site and you should read them if in doubt.
There is always these tiny words that say “your experience may vary” or you must reach 9999$ in irder to withdraw (example).
Beside this I do not know or heard of any game that says you can make money except of casino.
Ive played a few of these games. The trick is that ypure competing against other people who are as good as you are. Ive won money, but not as much as i spent. There are “free” levels, but they attract the most people, so its the hardest competition.
Also, they’re making money off your data. As they say, when you are given money from a company and not selling a product, you are the product.
Yes, you make money for them.l