Most people don't know you're only supposed to load a branch circuit to 80% capacity (either 12A on a 15 or 16A on a 20). Some kitchens have just one circuit, and we all have microwaves, toasters, crock pots, instant pots, air fryers, electric skillets, 12 cell phones, and a bunch of other stuff plugged into it. It's a miracle more kitchen don't catch fire. I guess we get lucky there.
The 80% loading is for continuous loads, but it is a good idea to adhere to this rule for all loads (I use it for all loads).
It is seldom a good idea to use an electrical device at 100% of its rating, since we know the capacity and electrical integrity of devices usually degrade over time.
There are special cases where 100% breakers are used (in industry), but you have to be careful that the entire circuit and every device/contact is also rated at 100% if you use such a device.
Kitchens in the US have had a dual circuit requirement for as long as I can remember (dating back to the late 1950's at least).
Kitchens are suppose to have "split-wired" 120 volt receptacles, ie: the tab that connects the upper and lower outlet on a duplex receptacle is removed, and separate 120 volt circuits are brought to each screw terminal on the "hot" side of the receptacle.
This does put 240 volts in these receptacle boxes, which is not a problem, since you still have only 120 volts to ground during a fault, which is no different than a 120 volt circuit.
There is much confusion about the term "hot", and I don't like to use it since it is a slang term that refers to the conductor in a 120 volt circuit that is not the neutral. The "hot" conductor must be connected to the short prong of a 120 volt receptacle, and the neutral conductor (which normally has white insulation, per Code) is connected to the longer prong/opening in a 120 volt receptacle.
Also there is much confusion between the neutral conductor and the green ground conductor.
The neutral conductor is generally near ground potential, but it does carry full current in a 120 volt circuit.
The neutral should always be insulated on its entire length, and treated just as if it where the "hot" conductor.
Current flows in a continuous loop, which is out the "hot" conductor and back to the source (typically the utility company pole-mounted or pad-mounted transformer outside your house, in the US) via the white neutral conductor.
The green ground conductor (it must be green in color per Code) is used for safety purposes, and what it does is establish a ground plane of equal (grounded) potential across all metallic items such as electrical conduits, metallic junction boxes, and the metallic frames of equipment and appiances.
The ground conductor does not have any current flow in it during normal conditions.
If the "hot" conductor happens to make contact with anything that conducts current in the system, the frame of that piece of equipment should be solidly grounded, such that the stray fault current from the "hot" conductor will immediately flow back to the upstream circuit breaker and trip it.
During a fault, there is no load impedance in the circuit, and so the fault current is high until the breaker trips on instantaneous (via a magnetic coil in the breaker).
Without a ground wire, under a fault condition, the metallic frame of a piece of equipment becomes energized, and there is no low impedance path back to the panelboard, so if a person makes contact with the metallic frame, current flows in the "hot" conductor, through the person, through the ground, and back to the panel, thus generally electrocuting the person (actually starts heart muscle fibrilation ususally).
I have seen many electrical cords with the ground prong cut off, for convenience.
This again is a "Corvair" moment, and is always extremely unsafe.
I don't use any extension cords that do not have the ground prong, and I don't use any electrical device that does not have a ground prong on the cord/plug, unless it is a device specifically designed to be "intrinsically safe" without a ground prong on its cord, due to double insulation or other means.