The total length of wire in a microprocessor is currently on the order of 100km. A signal doesn't have to go through all of it, but processing often involves loops etc. Also considering the delays at logic gates (waiting for clock signals), it's not that surprising that a speed-of-light signal that needs complex processing may travel longer inside a microprocessor than on a straight journey of a few thousand miles across the ocean.
I didn't say that network packets take no processing, just that the processing path matters. Contrary to your intuition, this path is significantly shorter for network packets, and an Ethernet board (first produced in the 1980s) is a much simpler circuit than the latest GPUs.
Transocean cables aren't just Ethernet boards on both ends. There's extensive, extensive gear on either end as well as at the peering points between you and the destination. I'd wager that the same packet traverses tens of microprocessors between you and the destination, so your point is questionable.
Just adding a router can add up to 30ms to a hop, if it sucks.
> (The electron wavefront travels at ~0.66 C in copper. I don't know about Si though.)
Copper doesn't have much to do with this, rather what is important are the impedance characteristics of the transmission line. 0.66*C is a reasonable number for thin coax cable. Split speaker wire on the other hand is also often copper and has a propagation velocity of 95+% of the speed of light. Generally the dielectric used and configuration of the transmission line is far more important than the type of material used as the conductor.
As for processors, signals are still moved around on metal wiring, the propagation velocity through Si isn't really important but rather the propagation delay of gates which is less about the speed of the wave front and more about how long it takes to turn the transistor on or off. While there is some component of propagation velocity involved in this, its not really significant in comparison other factors in the gate design (see Intel's Tri-gate).
CPU's are vary parallel operations, for instance each bit of a 64bit CPU needs it's own wiring. With the longest path for a single clock cycle being limited to ~4cm.
