(wrote good stuff here)
I certainly agree that the "one knife" concept is weird and contrived, and more in the realm of theoretical what-iffery than reality. The whole "only one knife" concept should be abandoned as pointless.
However, the Scandi type "bushcraft knives" don't even pretend to be a do-all tool, unlike the big "Tarzan A" survival knife. If a person claims that these knives are "do-all", then there is some type of delusion going on in that person's head, but that is not the fault of the knife. The Scandinavian style small belt knives are intended to be carried with an axe. So you've got one knife and one axe. If you can't do the job with those tools, then you probably can't do it even if you're given a whole team of half-naked Canadian lumberjacks with a couple of strippers to keep them happy during breaks.
Of course, since we can only carry so much weight, everything we carry is a compromise of sorts. It would be incorrect to claim that "indigenous groups" didn't carry a very limited tool set - they did. They had very limited tools "at home", and even more limited "out in the woods." Here in Finland, for example, the traditional set of tools carried by "indigenous groups" was a simple small knife (puukko) and a simple large axe. This very limited tool set of two tools, one for small work and one for large, was used to do practically everything from spreading butter on the bread to building a rudimentary cabin. Of course, it was preferable to have more stuff, especially a saw, but that often wasn't practically possible.
