Playing gambling for a long period of time will surely give user a sure loss due to human error. But as I said above, each round result is purely chance.
I looked at the opposite outcome, we are suppose to improve if we play longer, otherwise we are just wasting time and money. I'm referring to particular type of games where you can use your skills, but for luck based games, then you'll surely lose in the long run, not because of an error but because of the house edge, that's very simple to understand.