It’s because I have never seen a dishwasher in the US designed for a high current circuit.

Right. But, if they did make a 5000W dishwasher, it would not be difficult to power it in the US. Even though typical NEMA 5-15 and 5-20 outlets can only handle 1800/2400W, US electric code provides for 50A@120V, 20A@240V, and much, much larger circuits for ranges, water heaters, hot tubs, pools, arc welders, air compressors, etc. There is no electrical limitation preventing adoption of cold-water dishwashers.