The identical products produced for the rest of the world have all the scales and displays marked in Celsius. In fact in many countries you cannot sell equipment that is "non compliant" with the declared national standards.
As the American market is only a very small percentage of the world market, America will eventually be forced to change.
America still gets products, but will be tend to be few generations behind. The newest products are made for the metric markets and if capacity permits a few items for the the non-standard (imperial) markets will be built.
We already see that in HVAC systems and Power Electronics, where it takes like 5-10 years for innovation to trickle through to the American consumer. Most A/C equipment in the US is still single stage compressors, something you can't even buy anymore in Europe and many Asian markets. Variable speed is already fully adopted over there.
Here lies the issue with your argument, the American consumer in large is not a very demanding one. Americans don't go on the streets and block all interstates like the French when fuel prices go up etc.
USA Consumer tend to be fine with a rumbling A/C unit, having unreliable overhead powerline, the choice between one internet provider, random gaps on Tesla cars all around and roof material they have to regularly replace every 10 -20 years.
We in Germany tend to over engineer everything, ridiculous complex and precise and can not be repaired without going to school for 3 decades. The German consumer is very demanding and only wants to have the best and is happy to wait and to pay for that.
But homes are unaffordable at best, and metric fasteners don't help an unreliable BMW or Mercedes engine.