More current needs thicker wires. The average US outlet is wired for 120v15amp. 20 amp circuits are somewhat common, though 20amp receptacles are not. Certainly not enough for commodity appliances to rely on.
Going to more than 20amp requires a multiphase circuit which are much more expensive and the plugs are unwieldy and not designed to be plugged and unplugged frequently.
> Going to more than 20amp requires a multiphase circuit
There is no multi-phase power available in the vast majority of US houses. A typical residence has a 120/240 split-phase service, which is single-phase only. A service drop is two hot conductors from two of the three transformer phases and a center-tapped (between the two hot legs) neutral conductor. Either hot leg is 120v to ground and line to line is 240V.
Going to more than 20amp requires a multiphase circuit which are much more expensive and the plugs are unwieldy and not designed to be plugged and unplugged frequently.