Good explanation and what you convey is true that one of the reasons why the idea is spread is because it is a good idea to keep everything running in balance in terms of income and expenses and far from excessive, especially in terms of expenses, the point is that any idea that leads to prevention will always be good to do, especially in activities that involve the risk of losing money.

On the other hand, so far I personally still use a minimal approach in the sense that I only bet with a little money and even then not often, such as only on weekends when there are no family events then I will gamble, so for me maybe the idea is not really needed, but of course in general it is an idea that is quite recommended to do, especially if you are a fairly active gambler.