Even more extreme example - take a look at "High Tension" power lines... Compare the size of the wires to the size of the birds that are sitting on them.... The wires are skinnier than the birds and are carrying a lot of current, but are doing so at very high voltages (usually thousands of volts)... If the were running at "household" voltages they would need to be a few FEET in diameter, in order to carry the same amount of power...
At least in the US, even the local power is carried by the relatively skinny wires at the very tops of the poles, at high voltages... It gets stepped down in those garbage-can size transformers you see every few houses to the actual household power.... (Semi-amusing note, there is a perpetual problem with "suicidal squirrels" that try to step between the wires on those transformers...

Squirrel makes a brief welding arc, and mostly vaporizes... Problem is he usually blows the breaker on the transformer, which takes out the few houses it's serving until the power company can get a truck down to reset the breaker... It's so common the line guys I've talked with refer to it as a "squirrel outage". Biggest risk is that the flaming squirrel remains have been known to set fires to growth at the base of the pole...)
ex-Gooserider