Regionalized units have the same damaging effect to manufacturing as closed software ecosystems has to software development. The only reason most US citizens do not feel the pain of this fragmentation is that they do not have to buy anything that is not adapted to the US market. Again, this is because the US is the biggest market on the planet and thus it is profitable for big companies to adapt their products to US standards.

However, supporting several unit systems is a huge tax on startup companies that work in manufacturing and therefore they reduce innovation and competition, causing harm to everybody along the way.