Casinos can't allow you as gambler win when doing so is detrimental and dangerous to their finance, and this is the reason why the make there provably fair, which means player or gambler have 50 percent chances of winning, and 50 percent chances of losing their money to the casino, but the casino not willing to accept any form on loss, have to introduce house edge, to further increase the gambler's chances of losing his or her money to them(the casino).
It is important we all understand that it's humans like us that run online gambling casino, and this people need money just same as we the gamblers all do.
So, gambling is a game of, gambler verses the casino, whoever wins takes home the money, and as we all can see, casinos have been pretty good at winning, and the reason for this should be very obvious to those experienced gamblers.
In a game of man versus casino, the casino always wins. Because man is an emotional creature, he is prone to hasty and ill-considered actions, and a tendency to gambling. The casino simply figures out how exactly it needs to earn money, it is impersonal, and it has no personal intention to win from the player. Players tend to make mistakes that lead to losses. Moreover, they tend to want to win back, to recoup their losses, and this feeling often leads them to even greater losses.