I mean sure, you can learn basically anything if you put enough effort into it. Had a friend who refused to let builders build their house and did it all basically himself, took him some 2-3 years. Only hired aid when he needed more muscle than 1 person can muster (or to check if he did OK electricity and plumbing, but otherwise all by himself).

Motivation was 2-fold - obviously save some money, but also to know how to repair stuff once things start degrading, and they for sure will, one after another.

Sounds romantic and the right things, but as somebody who knows exactly what I want to do with my life and how to get there, its just another meh no thank you for me. One has limited free time in this life, the older usually the less, and I really don't mind shelling out few bucks to equipment from ie Decathlon (for US - good quality and cheap outdoor stuff, you really don't need overpriced Arc'teryx things) and spend free time actually using it out there. You only need few items to be proper high quality for not ruining the trip, ie shoes, backpack and maybe jacket for colder times. And of course technical stuff for ie climbing or alpinism but thats another topic.

Saving tons of hours on frustration on understanding how things shouldn't be done. That is coming from person whose mom used sewing machine quite a lot, grandma was making various clothing for all their grandchildren etc.

That food preparation part is actually more interesting since you control how much chemical crap goes into it (well, obviously apart from actual ingredients for it... but I presume since you invest so much time into this you go for ie free range bio meat and similar quality of the rest). But again - I can just pop extra dollar or two per dry meal for bio variant of prepared meals, they taste wonderfully after long hard day anyway, especially if one is properly hungry. Now if somebody would come up with dried usable beer that would be another story...