It has even reached the point of shoes with integrated socks.Depends what you call "premium". IMHO for dress shoes & boots, none of those brands are "premium" ... that term is reserved for English shoemakers who are several notches above them. Or maybe those brands are "ultra-premium" and we can knock "premium down to Alfred Sargent and Alden?
I agree, though, there was a shift from all shoes being "repair-able" to being irreparable. I think it was less about manufacturers making conscious decisions and more about the development of new technology: "back in the day" the only way to make shoes resulted in a product that could be resoled and repaired. At some point ... and no doubt linked to the ever-changing world of running shoe manufacture ... we reached the technological point where we could churn out shoes that looked "okay" and were not capable of being resoled. Those are cheaper to make, significantly so, and there you go.
How a $700 sock with a sole became the hottest sneaker in fashion