It is true that when it comes to outdoors, reliability may just be more important than performance, though that really depends.
I've been part of some government sponsored expeditions for which expensive stuff could be afforded, and shit, when you get your hightech backpack, shoes, coat and everything, nothing can stop you. You're never cold, you're never wet, your feet never hurt, your back never hurts, you feel like you could walk for a thousand miles, and you could probably do it. And I wouldn't have done half of it with my regular gear.
Performance offered by modern gear is outstanding. But then, yeah, its durability isn't exactly as good, though we're talking about 2 to 3 years of extensive use here before they start to show signs of age. Note that I'm talking about quality gear here, not just "expensive" gear, as a ton of expensive gear is actually shit.
If you want actually durable gear, just consider the materials being used: thick leather, thick canvas, animal pelts, oilskin, synthetic rope, steel, wood, copper, bronze, and polymers are your best friends.
These are the most durable materials you can find. Just stop thinking in terms of brands, and just try to get your hands on gear made of the following materials.
Expect lower performance overall, though certainly not "terrible" performance either, it's quite good, but then, it's fucking heavy.
Being able to go hiking alone is rather new. Back then when durable gear made of the above mentioned materials (except polymers and synthetics) was being used, people were always in large groups, and there were quite often carriers along with them. Someone on his own couldn't just carry his own clothes, sleeping gear, tent, food, water, toiletries and first aid kit. The weight was divided among everyone.
If you want to go the durability route, you'd better find friends, because you won't be able to do it alone.
