At the same time, I wouldn't underestimate the worldwide effects a ban in the US had, given its importance as a consumer of world goods especially in the second half of the 20th century. And while industrial hemp wasn't banned worldwide, it was banned or curtailed in other countries for prolonged periods (e.g. Germany from 82 to 95).
Hemp production seems to be around 0.25% of cotton production. No matter the intrinsic properties of the material, that seems like a very difficult lead to catch up to. And I'm sure both are getting squeezed by synthetic fibers (cotton consumption seems to be fairly stable for years).
Hemp: 65kt https://en.wikipedia.org/wiki/Hemp#Producers
Cotton: 25mt https://www.icac.org/Press-Release/2018-(1)/PR-5-2018-Global...
Synthetic fibers: 65mt https://www.statista.com/statistics/741368/world-synthetic-f...
Wool: around 1mt
Exporting hemp is also an issue. The USA foreign policy forced most of the world to make cannabis illegal since the 70s.
Since hemp was illegal, capital was invested in cotton and wood industrial tools.
As hemp production increases so will the technology to produce goods.
Over 30 according to a quick look at wikipedia.
Many countries around the world do not have the same restrictions on hemp industrial production that the USA does, and yet, hemp isn't all that widely used and other sources for materials are often preferred instead. I suspect a lot of the praise of hemp as some kind of miracle material comes from those who just want legal marijuana and they’ll say anything to get it, not people who particularly care about industrial manufacturing.