The "Amperage" of the breaker is sized to protect the wire in the wall.
For the most part it is working well as there are a lot fewer home fires than there used to be...
So the Amperage rating on the kitchen circuits will be determined by wire size. As a generall rule most house , hold wire is 12 gage, which is good for 20 Amps.
On lighting there may be 14 gage wire, and on appliance circuits cloths dryer is generally a 30 amp braker for 10 gage wire. The smaller the wire the higher the gage number or conversly the smaller the wire gage the larger and more amps (power) that it can carry.