First of all, the "speed of light" is usually referring to c, the maximum speed that matter or energy can move at.

Second of all, electrical signals in cables move at speeds slightly lower than c, but very close to it, so the speed of light is still a very good approximation of the possible upper bound.

Third of all, intercontinental cables are normally fiber optic, for several reasons. That is, they directly transmit light through the cable.

Fourth, it should be noted that electricity is actually the same thing as light, since photons are the carrier particles of the electric field (when two charged particles interact, they are actually exchanging a photon). It's of course not visible light, but satellite communication also uses radio waves normally, which are not visible light either.

Finally, either through cables or through satellite communication, the distance/c minimum theoretical one-way latency is usually a significant under-estimation of the actually possible minimal latency, since the straight-line distance is significantly shorter than the actual cable/satellite-and-back distance that the signals must travel - the difference in straight-line VS physical path distance is typically much larger than the difference between the theoretical speed of light and the actual speed of the electrical signal propagation.

We tend to think of wires as a garden hose for electrons, but it's the EM field that propagates, moreso than the electrons. Especially for AC power and for signals.

Most (all?) Intercontinental cables will be fibre optic. So it's the speed of light (in glass, not a vacuum)

I'm not an expert in cross-continent interconnects, I have no idea what cables are being used there. I'd imagine that a lot of the backbone of the internet is fiber because that's what all the SRE memes say about wandering backhoes and sharks being the primary predator of fiber optic cables.

Nothing is faster than speed of light. In fact signals transmitted via copper wires are traveling at 2/3 the speed of light. Don't know the details about fiber ocean links, but it certainly won't be faster than speed of light.

Fiber optics are also about 2/3rds the speed of light. One of the interesting things about Starlink is that when they have laser links between satellites they should be able to beat terrestrial latencies over very long distances like California to London.

would a satellite to satellite laser in low earth orbit be faster than a radio link between the same satellites?

only bandwidth wise. latency would be the same assuming that the transmitters and receivers in both cases can process the signal just as fast.

If you mean lower latency by faster, then no.

These cables are fiber optics, but either way, the speed of light is still a bound.