Hemp is sourced from Cannabis plants, which are (among many other things!) one of the fastest growing species of vegetation on the planet. This means that it has incredible inherent potential for industrial use, and so by no coincidence became one of the first known plant products spun into usable fiber (we have evidence of such spinning occurring upwards of some 10,000 years ago!).
This material used to be the backbone of heavy duty textiles, used in the production of ropes, sails, dining linen, work clothing... the word 'canvas' is derived from the word 'Cannabis' because of how ubiquitous hemp was in naval canvas manufacturing. Its largely tangential association with the narcotics end of the Cannabis plant led to decreasing popular use as drug control laws were enacted, but it has proven just too useful a resource to fade out of favor and has enjoyed a considerable resurgence as Cannabis decriminalization rolls out across most of the west.
Hemp creates a very no-nonsense fiber: it is tough, it is rugged and, while not at all unpleasant against the skin, it lacks any real softness. This is a material for gloves, umbrellas, coats, boots, cloth sacks... anything that one would expect to deal with rain, dirt, mud and abuse. There's a very good reason shipwrights used it for making their sails and rigging!
It is also very inexpensive, owing to its ease of growth, ease of cultivation and limited land use demands. It is perhaps the most ideal crop for someone looking to start a plant-based textile material producing farm.
For all this merit, however, it does still have a pretty STIFF competitor in today's fiber market:
Bamboo...