In my opinion making cash from gambling is not a good option and the statistical probability that you will win every game at every casino is very low. I think winning or losing every game is completely in your head, so your individual tricks are not there. However, we all have some kind of luck so we should strive for what is possible for us.
The short answer is basically yes. It is simply all about luck.
It is just a random process, and it is designed so that the odds of every game provided by the casino has more advantage to the casino.
That's pretty much it. Of course it is a massive industry and has many things around it, but at the end of the day it is a random event with odds not favorable to the gambler.