In fact, electrons are MUCH smaller and they don?t just sit there but are always wriggling around.
So the middle of this clip is actually more realistic - even if the electrons are harder to see. Also, we are still showing far too few electrons and showing them as bigger than they really are.
Copper has about 1023 atoms/cm3 and each atom shares a few electrons - so there are actually about 1023 electrons/cm3. Further, electrons are MUCH smaller than atoms. This wire would be at least a million atoms thick.