Let me try again with smaller words and shorter sentences.
There was a time when a rider who was unable to buy off the shelf tall boots to fit and couldn’t afford custom boots had no other choice but to show in jodhpurs and jodhpur (paddock) boots. Back then, there was no such thing as half-chaps, or tall boots with zippers, or a dozen different options of off the shelf boots from a dozen different manufacturers.
However, today, with the widespread availability of half chaps to fit almost any calf size/height, those people are no longer forced to wear jodhpurs and paddock boots. Instead, these riders will opt for breeches or tights with half chaps and paddock boots.
Although I don’t know why you couldn’t wear half chaps with jodhpurs if you were so inclined and the half chaps would zip up over the bulk of the cuff.