Oh man god bless ya. I said exactly this to an interviewer once when they asserted with complete certainty that copying a value from a register to another MUST be faster than copying from a pointer.

I said "I agree that it's probably true for mostly every piece of hardware you'll ever touch but I think it's theoretically possible to design a digital circuit in which for certain cases they take the same amount of time"

To which the interviewer said "No it is impossible"

The guy just didn't wanna hear me out.