https://www.rei.com/blog/camp/how-much-should-your-pack-weig...
Almost all of the pack weight should be on your hips, not your shoulders.
Good luck preparing for your next trip.
That's really heavy - any particular reason you need so much stuff?
75 pounds is 34 kg. A normally fit person should be able to carry that for several days without issue.
It's always a trade-off. You can take less equipment with you but be less effective when you get to wherever you're going, or you can take more equipment but have a harder time getting there.
You may simply be doing that something that requires 20 kg + of equipment when you get there, so not much much of a choice.
Weapon systems, communication systems, climbing gear, oxygen, tools, whatever.
I regularly hike with climbing gear, which as you point out gets quite heavy. I would very much avoid having that much weight unless it was necessary to climb safely.
For info, six days autonomy and including a bear can I’m hovering around 30lbs which is when the ultralight backpack starts being uncomfortable
I think that's about 13 kg. For six days? You must be on very limited water each day. 13 kg is running weight.