To me, a 10-hr window (eg 8am-6pm) doesn’t seem restrictive or even mildly inconvenient (definitely not enough to classify as IF), so maybe the insight here is that people regularly eat across all their waking hours - and not doing that is better.
It is just how devolved our modern eating habits are, we are constantly snacking or eating garbage which makes us hungry soon after. Three solid meals a day, cooked at home with unprocessed food ought to be good enough to live a healthy life but for the people who go on all sorts of diets, food has long become an emotional thing so they need restrictive frameworks in place to help them not eat so much/eat junk food. I bet our ancestor never thought this hard about what to eat and when to eat.
