Every non US market could impose their will, simply by banning imports of products that use, or reference SAE instead of metric.

For anyone else wondering WTF SAE is:

Tools and fasteners with sizes measured in inches are sometimes called "SAE bolts" or "SAE wrenches" to differentiate them from their metric counterparts. The Society of Automotive Engineers (SAE) originally developed fasteners standards using U.S. units for the U.S. auto industry; the organization now uses metric units.

https://en.wikipedia.org/wiki/United_States_customary_units#Other_names_for_U.S._customary_units