True but kettles rarely run for very long.

But computers do, which was why I included that context. You don't really want to build consumer PC >1500W in the US or you'd need to start changing the plug to patterns that require larger branch circuits.

Kettles and microwaves are usually 1100 watts and lower, but space heaters and car chargers can be 1500 watts and run for long periods of time.

Microwave ovens top out around 1100-1250W output from a ~1500W input from the wall. Apparently there's a fair bit of energy lost in the power supply and magnetron that doesn't make it into the box where the food is.

Microwave ovens have a different issue, which I found when I upgraded my breaker board to a modern one in my house. The startup pulse gives a type of load which trips a standard A-type 10A breaker (230V). Had to get those changed to a "slow" type, but even that will trip every blue moon, and if there's something else significant on the same circuit the microwave oven will trip even so, every two weeks or so (for the record, I have several different types of microwave ovens around the house, and this happens everywhere there's a 10A circuit).

The newer circuits in the house are all 16A, but the old ones (very old) are 10A. A real pain, with new TN nets and modern breakers.

Ah, 16A at 230v (3680W) is a normal circuit here. Most appliances work with that, the common exception is electric cooking (using two circuits or 380v two-phase) and EV charging.