My point was that they were less adaptable. For example, the climate changed and they were unable to adapt. I stated that they had bigger brains and more advanced technology. Neanderthals were more intelligent than Sapiens.
I had no premise that “most people were inactive”. I honestly have no idea where you think I said this.
A single human alone would probably die no matter when they were from. We have always been a social species. A group of humans would be fine anywhere that was not a massive extreme (desert, tundra) unless they had experience in these locales.
Anthropologists know that ancient hunter gatherers were stronger, fitter, and typically had lower rates of morbidity than us. Which kind of undermines your “agile” and “tame” bit.
I’d also say going from nothing to stone tools counts as quite resourceful, if you ask me. Given that our ancestors had the same basic wiring and larger brains, I’d actually wager on them being more curious and clever than modern humans.
The point is that our ancestors up until 10,000 years ago would make us look like complete and utter wimps, which contradicts your “most people were inactive” premise.
And based on what happens to a modern human even with survival gear who gets lost in the wilderness, typically death within a week or two sans rescue, I genuinely doubt that modern humans would adapt quickly enough to a hunter gatherer world.