It would be nice if our bodies could adapt to modernity quicker, like don't prioritize blood clotting over immune defenses, I can just get some more band-aids on the off chance I cut myself in our very safe world. Don't preserve calories in case we are starving in the future, just build muscles and heal injuries recklessly I can hit up the grocery store if we need more nutrients.
The problem is also that if you "adapt fast" to "recklessness", then many people die fast before they would not be able to adapt back if necessary.
Got wounded in a conflict zone cut off from supplies for months? Too bad, coz your body adapted to grocery store being close and unfortunately your body decided to just never put on weight in the first place, so now you have zero reserves to use up and ... you die.
Watch "Alone". Some of the guys are adapted to never put on much weight and that's a real problem for them. They have a TV show safety net. If it was real, they'd be dead.
Asking because "my bow guy" from Youtube, that I learned bow making from was the winner of Alone season 8 and he's one of the guys that can't put on weight. He tried i.e. put on as much as he could but he knew he had a disadvantage against everyone else because he'd not just go in fat like most others.
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stop reading here if you did not watch season 8 and want to not get spoiled
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Clay Hayes if you want to google his channel. Does survival stuff, bow making and bow hunting / trad bow.
He won, because he knows his stuff, so while the guys that had just put on weight had a weight advantage, he had a knowledge and "actually knows how to survive off the land and has nothing to prove" attitude. While some others had their bow strings chewed up by mice, he immediately hung his bow up. Unlike others that built elaborate shelters and used up all their calories, he built a very simple a-frame hut that he knew how to build. Even though he had no proper clay he built a proper tiny oven to keep himself warm and smoke free inside. He had absolutely super bad luck with fishing. Essentially got nothing for lots of effort.
He was super lucky in that he actually found a deer and was able to shoot is with his trad bow, which is because he goes deer/elk hunting for real every single year with exactly that setup (see his youtube channel). He knew how to preserve said meat by smoking it and he knew how to protect it from the bear(s) in the area, which they weren't allowed to kill because this was filmed in BC Canada. He even had a super close encounter towards the end IIRC with a cougar but might have been the bear, not sure any more (not around his meat but out and about).
He almost gave up. Basically he wanted to give up at the next med-checkin because he essentially had no food but the smoked deer and they told him he won!
I also remember not liking how restricted each person was - they were plopped on a plot of land and couldn't roam or move if they got unlucky. Also in that they were limited in what they could hunt / survive on. Its been awhile though so might be a bit murky.
There's plenty of research showing that brain development and food preparation went hand in hand (cooking allows humans to liberate more calories from food with the same sized gut, allowing us both to be pretty mobile and have more energy available to run our large and energy-hungry brains).
If you look at the way guts are built, clearly nature/evolution is trying to pack as much intestine as possible into a limited space.
Certainly increasing calorie availability beyond a certain point isn't a good thing - our brains can't burn more than a certain amount, and most of us, Michael Phelps excepted, don't like making our bodies do the same - but I wonder to what extent our design-constraints put limits on our ability to absorb non-calorie nutrients.
On the one hand you have a supplement industry who will say anything to make a buck, and are infected with pseudoscience and woo, but on the other, the standard med-sci advice of "just eat a balance diet, it's impossible to improve on that" seems kind of glib and baseless.