I have been working for many years, and I remember only few cases when I managed to spend more than I have earned. These were emergency situations with health issues, when I had to act quick and borrow money. In every other case I save, but sometimes make large spends on vacation, flat renovation, transport purchase. Such things does not happen every month, they are planned before. So yes, saving each months aint that hard.
People with small salary will be able to save more and spend more, in cases where their expenses are less. On the other hand, I have seen some of the high earners struggling to balance their monthly budget, because of sky-rocketing medical expenses and home loan EMIs. So different people may have different ways to deal with it. And also, it need to be seen whether saving money is a good idea with the current inflation rates touching two digits. Stock markets and bank deposits now offer returns considerably lower than the inflation rate.
And you are right the more the rich the more overspending habit they have and middle class tend to spend less and cautiously because they know if they are going to be careless about finances they can end up broke by end of month.
I just also recall that before my salary is too small i can say that it is enough on me but now when it was way more bigger than my previous salary we always caught of short i think this because of the inflation and also over time when we do have bigger salary our spending would be also bigger like before we wont be eating on restaurant but now as you have bigger salary you will now it their which means that you do have intended budget on it.
However, no matter how you plan to work with your spending, a good income is the determinant. If the pay is low, it would be hard to save regardless of how much you try to cut spending. This is why it's always good to hustle well or secure a paying job that gives way more than your expenses.
I know that it is not healthy, but this kind of bonding with my family and we can eat delicious food doesn't mean that my cook wasn't delicious; it is that the food in restaurants is different from what we cook at home, and some sort of thing. We are happy eating outside the house, though we don't do this regularly, only once a month or if not every other month, as it is expensive.