If someone wants to train their mind, they can still go for other mind games that doesn't actually require them to gambling with real money, some people can feel convinced that gambling can train their mind but once they dive in, it becomes a different story entirely. I don't disagree with you that gambling is a mental sport but in the way you described it, it's result will be different for every individual, it can only be used like that and would prove positive result in some individuals but for many people, you will get an opposite result since they would have a biased thought, not to stretch their mind again but to make money from what ever game it is.
I agree with you. Initially, when I started playing skilled based games like poker and cheese games, my performance was very good and that made me feel like a pro. Whenever, I stake on the game, I hardly win it because it messes up with my emotions and I don't concentrate properly compared to when money isn't involved.
It happened several times, I stopped betting and only play the for fun. Some people are also like this, they don't have a settled mind when they bet money on the game that they are involved in directly. I prefer sportbet because it doesn't involve you playing on the pitch.