The UK didn't have any problems changing over. Anyway, most electronic
thermometers give you the choice to set C or F.
OK, but...
There are many more thermometers in current use that are not
electronic.
My house is only 44 years old and the thermostat is F.
It's about the installed base. You're free to use whatever scale you wish.
In the USA, using F provides the best communication with other
people in everyday life.
If you told me it was 30 degrees outside, I'd assume you meant F.
If you told me it was 30 degrees C outside, my reaction would be,
"HUH?". It's not that we can't do the math, but why should we.
If my oven is F and the cookbook is in F, there's no upside and some
downside in trying to
use C anywhere else.

We changed from F to C years ago. It really doesn't take long to adopt
the metric version.
The USA is one of the very few countries that don't use the Celcius scale.