That's a gamble.
I've done that with my friends when we go from places to places just to play competitive games and have money on the line. That's normal for most of the games even in RPG games where there's PVP. I've seen people betting on who's the strongest.
Today, with most competitive games are online, it's easier to bet and have someone on their end that will just have to pay and sent the payment through online transfers or crypto, too easy to bet and play these days.
Most of the games for stake come with a contest involving multiple players trying to win a prize by placing a small bet and that is how they are usually made of money to fund that settlement. But in tournaments, the costs for event organizers are more than fees.
It's just the idea of putting money in and getting more in return, but on an in-depth look at the scenario, it could be different. Likewise with playing to get the game.
An investor will invest money as capital to get more money from the game. "more serious competition with serious & skilled players". It's not about making money, it's about participating and playing against good players, it's about how you hone your skills.