I wonder how US-specific this phenomenon is. UK dealerships don't seem to have a problem stocking them, and have been quick to pick up BYD franchises.
The US specific part is that a decent portion of the population makes, at least occasionally, longer trips outside of urban centers where more limited range, longer charging stops, and the need to carefully plan routes to hit chargers (that are hopefully functioning) make ICE derived power more attractive.
I'm actually out of date. The last time I searched (Dec last year) it was the case that it was quite hard to find any EV brand that wasn't Tesla. This appears to have changed as now I can find most EV brands in local stock.