Which is not a problem for dedicated circuits (you could wire receptacle just for this specific dryer / hot tub / RV / whatever, plug it and never remove), but would be a bigger problem if 240V is shared between appliances.
I think, NEMA 6-15 / NEMA 6-20 would be the best (they look very similar to standard 120V outlets; they have tamper resistance; 15A or even 20A should be plenty enough), but nobody wires them.
Also, there are other minor differences like:
1. 50Hz in Europe vs 60Hz in USA. 2. The voltage between ground and "power" lines would be different. In Europe it would be 240v between line and ground and 0V between neutral in ground, in USA it would be 120V between ground and both power connectors, due to how 240V is typically delivered to single-family homes in USA (split phase). Should not make much difference (you are not supposed to have any current to ground anyway, and any short-circuit should trigger the circuit breaker), but maybe it will affect safety somehow? 3. Seems like in some cases in USA you can get 208V instead of 240V (and Europe is nominally 230V).
- importing tools from Europe can kickstart the market and is a lot less risky than designing new tools
- 240V garage & exterior outlets are becoming common for hot tubs, RV's and electric car chargers.