Paradoxically, back when the market was LESS efficient, the extra slack afforded higher standards because they could overengineer something and still sell it easily.

It always comes down to supply and demand. Supply of generic products like compressors and blenders skyrocketed. Increase the supply enough and you get a race to the bottom. All market inefficiency has been squeezed out of the market. The market has arrived at an equilibrium of making some things just high enough quality that they last longer than a few months while being as cheap as possible. Anyone trying to make something higher quality gets squeezed out. Unless there's also much higher demand to compensate for it.