I also assume that it is true that everyone loses in the long run. You might get lucky a few times but if you keep playing, you will eventually lose.
Of course, that is the power of probability. It has been designed so that you will always be in the disadvantage.
Well you can make your calculations if youre not a greedy person wanting to make money fast; you can always gain profit; just make a small bet and deposit a large sum of money; there is no way that small bet is going to accumulate to drop your large value to zero.
So Its depends on how to take up gambling and with which mindset.