Not sure about 'Dominance' for narrow racing tires....
BITD, even during the heyday of the 70's bike boom, majority of '10 spds' (and 12 spds) came with 27 x 1 1/4 = 32 mm
and before that the 'racing' peloton/crowd was a tiny segment of any riding - remembering the year I got my USCF license, my member # was just below 16000... (that's nation wide).
real 'touring' was even a smaller segment - but you could get 700c sewups to 32, no problem...
wonderfully, the universe continues to expand... pick your flavor...
Ride On
Yuri