Do you mean "frontloading" the year? As in 1000 jan, 900 feb, etc? Or was it a typo and you meant decreasing your spending?

Smoothly decreasing every month for the entire savings period. Maybe it isn't popular because income tends to increase over the course of a career?

It doesn't make much sense to do logically because you can front-load a lot less at the beginning of your career. It's far better to design a sustainable lifestyle you like when starting out and aggressively fight scaling it up with your income. If you do that the numbers will work themselves out.

On the other hand, rising disposable income is supposed to be a good thing (annuities for lottery winners etc). Cost of living tends to rise with age, too (kids, healthcare...).

> rising disposable income is supposed to be a good thing

That's the lifestyle inflation I'm alluding to. If one can be happy spending X/year 5 years ago, why can't one be happy spending inflation-adjusted X/year today?

Agree about kids and healthcare but those aren't "lifestyle" costs.