An electrical signal travels close to the speed of light (not the electrons). Even when of course no light travels inside the copper.
If something oscillates at 1 GHz, 15 cm down the wire the phase is opposite. To me it's perfectly correct to say that speed of light affects the design a lot and in many places probably is a bottleneck.
If something oscillates at 1 GHz, 15 cm down the wire the phase is opposite. To me it's perfectly correct to say that speed of light affects the design a lot and in many places probably is a bottleneck.