My impression is that (intermittent) fasting is just a convenient way for many people to decrease their overall calorie consumption. I personally prefer eating low-carb for the same purpose.

I've always seen it as a "candle that burns twice as bright lasts half as long" type thing.

Like, if you want a car to still be roadworthy in 20 years, how often do you drive it? Not never, not all the time. You want the little old lady who takes it to the shop once a week.

No, practices like time restricting eating do more than that, into autophagy, insulin exposure, diurnal effects, SIRT1 and AMPK, and on. You can eat an equal amount of calories in a smaller window of time and see benefit.