Actually back in the old days string sets WERE balanced and "odd", but there were few manufacturers (think about the classic Labella sets, or Pyramid)
The same with guitar strings: once the sets were balanced in tension, but when ernie ball and other string makers came out, they standardized the gauges.
I dig the Super Light set of Fender Pure Nickel strings (for guitar), that was a leading set in the 70s, but no other brand makes that exact gauge, in particular noone does the lighter G string that set has, except a few.
Rotosound "standard gauge" set is actually NOT a simple 45-105, and measured with a digital caliber (on five different sets from different periods) is always 48-63-82-103, so it's well balanced.
D'addario, GHS and Ernie Ball have precise gauges for every string, because they were born as "string makers for others" and sold singles. Ernie Ball was the first to sell singles.
I think that at a certain point (probably the 80s) the habit took place, and players got used to "even sets with not balanced tension", until today, that internet let us buy sets we usually couldn't find in stores.
I discovered "balanced tension" when I tried Thomastik flats four years ago, then fell in love with Pyramid Gold short scale set and labella 1954, and few months ago the Thomastik jazz round set all perfectly balanced with almost the same tension for every string.