Itchy is maybe exaggerating, but as far as I know, lower class clothes were very coarse compared to modern ones.
A lot of natural fibers need a lot of strength to be spun into finer threads and we didn't really have that on a large scale until the 1800s.
Plus distribution was much harder so in many remote parts were stuck with whatever they made locally, which was most likely subpar even for their times.
Cotton tech in the 1800s really revolutionized clothing.
