Always remember that luck also matters in gambling but using betting strategies and math can improve your chances of winning the game. In games like poker math probabilities and game theory. Regarding the value of school some disagree, but skills from subjects like math can unexpectedly help even in gambling.
Yeah, luck and strategy matters here in gambling but their dependency can differ on what type of game we are playing. Some games needs more luck, while the other needs more strategy. As for the math part. Gambling is mainly compose of numbers. From the odds or probability of winning, to the house edge, and so on... .
But when performing a strategy on some games, a math can also be involved there. Like for example in some card games, there is a strategy called card counting. School subjects like math and many others can help us in our daily life, not only limited when we play gambling. So, not just some but many will disagree on what the OP have said there.