Depending on your country laws, in the country I came from you are allow to to bet any amount you wish to bet with. But when betting it is advisable you bet amount you can afford to loss in order to free your self from emotional Truman, I have not try on betting on casino game I mainly focus on football betting which you are allow to play with any amount you wish.
Well, I believe that op wasn't referring to betting on casino games, but on sports games, betting on casino or slot games (from my experience) comes with some limitations due to the limit in winning amounts, I don't know if this is general for all casinos but I've only discovered this on one casino where as a test, I tried setting my betting amount really high but I got a warning pop up telling me my bet amount is too high and above the limit allowed, so, I had to bring it down to a normal level.
Anyways, the concern about responsibly gambling isnt something that is peculiar to your country alone, its a general concern and even casinos themselves always warn their players to make sure they are betting just as much as they can afford to lose, so as for them to maintain a healthy gambling experience.