I = V / R
And a light bulb needs X amount of electrons flowing per second (I=amps) to create light. Why do we use watts on the first place if all the light bulb cares is the number of electrons flowing per second (amps) to do the job?
My point is that, what creates the power (a.k.a. watts) for the light bulb to light up is the flow of electrons per second (amps), period.
Thus watts should be the same as amps(
P = I) if we just want to use another word.
For example we can have a circuit with different volt and different resistance and deliver the same number of amps and both will light up the light bulb.
I = V / R I = 10v / 2 = 5amp I = 5v / 1 = 5amp
PS: I'm talking exclusively about electricity.