Pickups do make a big difference in tone compared to guitar body woods, but it depends on what you are doing to the guitar signal.
In the video below, the point he is trying to make is that pickups don't make a huge difference IF you are applying high-gain distortion or a lot of processing to the guitar signal. He is also showing that changes in speaker, cabs, mic and mic placement have a larger difference. This can also be easily seen when using guitar modelers and changing IRs (Impulse Responses) which model the speaker+cab+mic signal path. Changing pickups in a high-gain sound just don't affect the sound as much as the IRs.
For electric guitars, let's reiterate the signal chain:
Vibrating string --> Magnetic pickups --> Controls --> Signal out
People hear the guitar as
Signal out --> Pedals --> Amplifier (maybe effects in the loop) --> Speaker+cab --> Ear (In the room)
OR for recording
Signal out --> Pedals --> Amplifier (maybe effects in the loop) --> Speaker+cab --> Mic --> Mic Pre --> A/D --> recording --> speakers --> Ear
So you can see that there are a lot of points where the sound can be changed/manipulated.
If you are playing very clean, the distortion introduced after the pickups is not as much, therefore the pickups are emphasized and probably can be differentiated more easily.
If you are playing high-gain and lots of distortion, this means the components after the pickups are changing the sound a lot but in a way that compresses the sound and shapes it towards a specific response that obscures the differences in the pickup response.
Physics can explain all of this because each component in the signal chain above has a function that changes the input. And some change the (dynamics, compression, frequency response, harmonic distortion) much more than other components. Hence this is why those components have more of a sonic effect at the end.
Pickups are just one part of the signal chain. But can be obscured by components after it.
In the video below, the point he is trying to make is that pickups don't make a huge difference IF you are applying high-gain distortion or a lot of processing to the guitar signal. He is also showing that changes in speaker, cabs, mic and mic placement have a larger difference. This can also be easily seen when using guitar modelers and changing IRs (Impulse Responses) which model the speaker+cab+mic signal path. Changing pickups in a high-gain sound just don't affect the sound as much as the IRs.
For electric guitars, let's reiterate the signal chain:
Vibrating string --> Magnetic pickups --> Controls --> Signal out
People hear the guitar as
Signal out --> Pedals --> Amplifier (maybe effects in the loop) --> Speaker+cab --> Ear (In the room)
OR for recording
Signal out --> Pedals --> Amplifier (maybe effects in the loop) --> Speaker+cab --> Mic --> Mic Pre --> A/D --> recording --> speakers --> Ear
So you can see that there are a lot of points where the sound can be changed/manipulated.
If you are playing very clean, the distortion introduced after the pickups is not as much, therefore the pickups are emphasized and probably can be differentiated more easily.
If you are playing high-gain and lots of distortion, this means the components after the pickups are changing the sound a lot but in a way that compresses the sound and shapes it towards a specific response that obscures the differences in the pickup response.
Physics can explain all of this because each component in the signal chain above has a function that changes the input. And some change the (dynamics, compression, frequency response, harmonic distortion) much more than other components. Hence this is why those components have more of a sonic effect at the end.
Pickups are just one part of the signal chain. But can be obscured by components after it.