One aspect is many one ton srw owners didn't want a drw and a rougher ride....or didn't need 4 tires and 10500 lb rawr payloads.
Most of us are old enough to remember for years all we had was 16" and later 16.5" tires and wheels. Thankfully the 16.5" were dropped in favor of our current 17"/18"/20" tires and wheels. New OEM 18" and 20" took a while for wheel and tire mfg to mass produce enough for all the LDT manufactures.
It will be interesting to see what Ram/GM/ Ford truck mfg come up for the next new gen mass produced higher capacity tires and wheels as gawrs on these trucks are steadily going up.