[skissane]

> A lot of traditional units are based on random reference points that were an issue from antiquity - consider how pretty much every market town kept their own measure references even if they used same terminology.

A lot of that was because keeping the definition of units consistent across time and space was very hard in ancient and mediaeval times, even the first few centuries of the modern period. Units were defined in terms of physical artefacts (as long as this metal rod, as heavy as this particular stone), which tended over the centuries to be lost or stolen, or slowly decay. Issues such as expansion and contraction of metals at different temperatures were also not widely understood, and accurate/reproducible thermometers didn't exist until the 18th century. As we improved our knowledge of natural science, we became more and more aware of these issues – but the initial solution was often just to make the whole country adopt the standard of the national capital, and empires were made to adopt the standard of the imperial capital (the British don't call their traditional units "Imperial" for nothing)