It sure didn't happen overnight.
And honestly with the very latest technology like the platinum Big Agnes fly creek three man tent at an even 3 pounds, Kifaru dyneema <3 pound packs, etc, more weight could be shed these days.

My first sheep hunt I did in jeans/cotton shirts and coats, my pack was 65 pounds without rifle! and I literally took pots and pans with handles on them... Crazy.
After we about died of hypothermia with a shredded tent--we had record rains that year--soaked clothes and exhausted bodies we resolved to be as light as technology and a sane budget would allow.
The rest was history.

And that 1.5 each/day seems like a heavy weight for food, Luke.
At least for us...Of course we could pack more.
If one is using dehydrated stuff, the weight is in the water.
I don't think we take more than ten pounds total for a week for all.
Lots of dehydrated berries, lots of oatmeal, couscous, small oriental noodles (not ramen)...couple of bear creek soups.
We've always been blessed with sheep or goat meat to round out the week. smile