15 amp circuit #14 awg wire, good for 12 amps, 1440 watts maximum, continuous load, 15 amp c/b no matter how much it’s loaded. 20 amp circuit, #12 awg wire good for 16 amps, 1920 watts maximum, continuous load, 20 amp c/b no matter what the load is. These are constants, across the country, no variables. No Electrical professional on the planet arbitrarily puts a smaller breaker on 15 or 20 amp circuits. PS, circuit breakers are really short circuit protection, not so much current limiting. Anyone depending on a $3.50 circuit breaker for current limitation will be surprised when it doesn’t trip upon exceeding the rated capacity...
Most circuit breakers if not tripped on a regular basis, may never trip, it’s called “exercising” your circuit breakers, should be done once a year, but no one does it, read rolling the dice. Consumers need to heed warnings, do it or not. Can’t make it more simple, out.