But i think a lot of them comes out of the same fabric. You can't have that amount of fabrics as there are brands in an economic way.
With strings i see and hear very little difference between the high G-B and E string. And that difference is just a matter of taste. By the lower ones the difference is more.
But the main point is to change strings regularly to get the bright sound.
Also there are guitarists who wants that old string sound.
I don't like the sound of brand new strings, after a day it sounds better.