I agree with you. Imho, modern man is too dismissive of early man’s intelligence and adaptability. Our ancestors may not have had our access to technology, but I believe that they were equally capable, if not more so. They had to be, or they didn’t survive.
Shoot, 'modern' man is even dismissive of redneck tech! I can't tell you how many times a city boy has preached to me about how dumb I am while I am fixing the things he doesn't know how to fix.
Knowing your penchant toward religious things, I might bring up 'false signs and wonders' and the bowing down toward 'sophistication' that they produce. True things are invariably far more simple... and in my eyes, more elegant.
Folks that have never hunted their own game and harvested their own greens are already so far down the rabbit hole of sophistication that they seldom can see what lies above. You are absolutely right that they were infinitely more capable. Even as our father's generation was more capable than us.