This is one of my favorites. Merlin in this always cracks me up. Also the protagonists learned knowledge is fascinating to me. The guy goes and creates a bunch of stuff from scratch and knows all the bits that go into the things. I always wonder if my education had been lacking, just because of this story.
My sense is that there was a sweet spot in the late 18th to mid-20th century when modern(ish) things were still built by human hands, mostly using simple tools, so people could learn to build (and repair) those things for themselves. That accessibility was partly recreated in the 80's with the PC, but things have shrunk down and become hermetically sealed with fewer ports, switches and physical buttons. And memory density has increased to the point where even sophisticated users will never understand all the software running on their machine. Cars have become far more complex than their mid-20th century counterparts, to the point where few people even check or change oil.
Americans are born and bred these days to be administrators of some kind, where all physical and digital goods and services can be purchased on the virtual open market behind touch-sensitive glass. If that glass breaks, you call a (low status) worker to fix it; if something behind the glass breaks, you complain to a (slightly higher status) worker to fix it. You yourself don't do or make anything - you allocate funds and then, at most, measure progress and outcomes.
Such an admin does not make a usable character like that in Twain. In fact, neither would either of the two low status workers, since they only "make" at the tip of an enormous world-spanning supply chain. You'd need to be a machinist, metallurgist or chemist with an interest in low-tech methods. Pretty rare.
High goods prices relative to wages force you to learn to fix stuff if you want to, like, have things that work (or, at least, they encourage quite a few people to learn how to fix stuff, so they can do it for others, for pay).
High wages relative to goods prices means everything's disposable. I might try to repair a $300 toaster. I might pay someone else to repair a $600 toaster. I'm not going to try to repair a $20 toaster, and I'm sure as shit not gonna pay someone else to fix it. I'll just buy a new toaster.
[EDIT] incidentally, saying "there's too much waste of X" is, in most cases, nearly identical to saying "X is too cheap". See: food waste. "Why do we waste so much food?!" because it's so cheap relative to labor that it's not worth the effort to waste less of it.
