The US is different.
Your typical household electrical is 15A, you then have 20A single pull and then double pull circuit breakers.
You have various outlets based on the power draw. Your typical appliance , electrical gear is going to be Nema 5-15 and its a 15A circuit w 14ga wires in the wall.
You can go w 20A circuits , single pull or double pull and then go w different outlets in the wall. I have NEMA 5-20 outlets for washing machine, and for my power conditioner/battery backup for my mini rack. Then a different connection for the dryer …
But getting back to audio gear. Depending on the power requirements you will see your bog standard power cables mostly using 14ga wiring while those that would pull more power… (e.g. 1000watt power supply for a PC) will have 12ga wiring.
Also while not an audio thing… depending where you live in the US, the building code will vary. In Chicago, no ROMEX wiring in conduit… yet in places like TX and elsewhere you can use ROMEX.
Of course none of this matters for you in Germany.
As to the impact of the power cable on sound… YMMV again like speaker cables… there are several factors… (which you can see above. )

Oh Mikey, please stop.

Mikey, you won’t get rid of that thing. This lapse on your part says everything about your faith.