I think that's how most players do it, responsible. Either they have a pre-established threshold that they don't exceed, or maybe they exceed it a little but they are able to stop, leave and come back another day with a fresh mind to try their luck.
The problem is the problem gamblers, who don't stop at the limits and end up losing much more than they should.
I think it is also important to set a time limit because as we know gambling is completely random so you could literally play for hours and at the same time you could breakeven, so even if in monetary terms you have not really lost a single dollar when it comes to the time that you have invested when you gamble the amount is not small at all, so I think it is important to also keep track of the time spent at the casino since there are several other activities that we could be doing instead.
Setting time and money limits is important in gambling so we don't use our spare time just to play gambling. Maybe if we have a lot of free time, we can use it to do other things so that our minds will not only think about gambling. This is also to control the use of your money so you can use that money to fill other needs and you can also use that money to buy things you want.
Gamblers who have a problem need to realize that something is wrong with them so they can start changing it, at least for themselves. After that, they can try to reduce the time they play gambling and that, of course, will also reduce the use of their money to gamble.