“Few”, yes. But definitely some. I don’t think you can have propagation of EM wave through a conduit without at least pushing one electron into the conduit and removing one electron from the other side of the conduit.
I was pretty surprised about this since I had mistakenly believed that electrons had a velocity near the speed of light, which I think is only true in particle accelerators.
In short, nearly everything I have learned is from saying dumb things in front of very smart people who instantly understood my misunderstanding and knew exactly how to explain it so I understood. That includes Sanjay Ghemawat and Jeff Dean telling me "your idea isn't so good, it's n-squared, here's a linear solution"
AlphaPhoenix did an amazing experiment to measure the speed of electricity FWIW. His other videos are incredible as well and explain EM physics in an absolutely outstanding way.