Of course the casinos will have an edge in their games, why would any company over free money? But even if our winning chance is below 50% it is not 0%. So why are we idiots if we like gambling? Just don't go in with the expectations of winning a lot of money. It is more likely that we are losing than winning in gambling, but we still have the chance to win. Putting our money in a savings account won't give us any real return. At least with gambling we have a chance for a nice pay day.
Considering your point, putting your money in a savings account also won't harmed you and not going to take risk of losing it all.
The fact that gambling is for those who have that nerve to take the risk and have a good will in accepting whatever outcomes happened after playing,
if you can't deal with that better not to play any game.
There are many ways to entertain yourself, gambling is part of it or if you are aiming for making money better to find other alternatives.