One of the differences between bushcraft and hiking is how surplus is viewed. In my experience, most of it is heavy, bulky, uncomfortable, and often made to the cheapest spec (hence the often robust but heavy and outmoded materials). Its also often pretty knackered by the time it gets to the civvie market, and its often not exactly cheap compared with the civilian equivalent. Its also worth remembering that there is a thriving industry in modding, upgrading or outright replacement of issued equipment . If its that good, why would people who get it for free spend good money on replacing it? BEING VERY NEW TO ALL OF THIS INITIALLY WHAT ATTRACTED ME WAS THAT TO ME IT WAS CHEAP AND WORKED WELL
Weight/comfort is very important to hikers - (BUT WEIGHT/BULK, AS I SAID, NOT TO ME CANOEING. I WOULDN'T HIKE FOR DAYS WITH SOME OF IT ON MY BACK......MIND YOU I USED TO AS A YOOF....I'M NOW 60) you dont have to be a gram counter to look at a surplus sleeping bag, softie jacket or rucksack to think that your money might be better spent on non surplus. Military gear is designed to put up with lots of punishment, but the average hiker has no need to carry stuff for weeks at a time, sleep in a ditch under fire, or carry a huge load, including ammo, etc. And although that natural materials vibe is suitable for some, if it means carrying 5kg extra for 30miles uphile, most will chose something else.
Put it this way - no hiker is going to buy a Lavvu, (MANY DO IT SEEMS.....) and although the Carinthia sleep systems are popular with the military and bushcrafters, you'll be hard pressed to find one sold by hiking shops for the civvie market. (COULD IT BE THAT ITS NOT KNOWN IN THAT MARKET, BIGGER MARGINS SELLING THE LATEST GEAR? I DON'T KNOW..... NO, YOURE RIGHT, NOT FOR HIKERS)
Its whatever the person wants, and whatever suits. (SO TRUE) I have to admit I've still got a cheapish basic rucksack from about 1991 which is perfectly usable. The inside waterproofing might have delaminated a bit, but it will do the job, and is fairly similar to one of these things
https://www.cnfoutdoors.co.uk/pro-force-trooper-65-olive-rucksack?gclid=CI3B2p7K8c8CFdMV0wodVKgKUQ - there is really no 'back system' to speak of, but its certainly not brittle.
(I STILL HAVE A 40YR OLD SLEEPING BAG IN IMMAC CONDITION FROM WHEN I WAS 21, SYNTHETIC. BLACKS HIGHLAND)
On the other hand, pretty much all the surplus stuff I've bought over the years has ended up in the loft, emergency car kit, or off to Oxfam. And those canvas bags with the metal strap ends were always a pain.