Gambling is not a scam because you were not promised to be rewarded after placing your bet. It's only a try your luck game which you are aware of. Gambling is for fun and you are to pay for having fun in a casino but you still have the chance to win back your money or more if you're lucky to your while having fun. Nobody will sweet talk you into gambling, only if you fall for those influencers but the greed of reaping from where you didn't sow is the problem, because you know that the chance of winning your bet is 50-50 and you went ahead.
Buddy you're right, there was no assurance from anyone or gambling institutions themselves that one will either win or be given something in return once you gamble, gambling is just an activity that is not assured so if you win fine and if you don't just take it as it is because even the owner of gambling firm do not no the outcome of any gambling event so is just luck all the way, though some people see gambling as fun and other see it as a serious event that can be used to make money but for me I will advise that it's better to see it as fun so that one will not be expecting much from it, yea there is possibility of a gambler getting his money back while having fun as you said but such chances are also slim though it depends on individual luck which can't really be ascertain.
Mate you just nailed it, some persons are bent on chasing after something the cant control, they attach so much greed and most times they fail, personally I gamble but not with tue hope that I must win, I have come to the understanding as a gambler that we don't have to chase after shadows, once past events are gone whether we win or lose, we can now concentrate on the present event and keep hope alive for our luck to shine.