[kinj28]

Curious if like internet cable - can there be redundancy built?

Also the way data packets go - they can go literally from any of the lines and get assembled together somewhere in the network layer. But same doesn’t hold true for 3 phase power. So same that works for internet wouldn’t be applicable for power distribution.

[EnigmaFlare]

The DC Cook Straight cable in New Zealand has 3 cables with one spare and one redundant. It can use the earth as a return path though, not sure if you could do that all the way to Singapore. DC doesn't have phases so it's not 3-phase, same with the Sun Cable.