When was BGP? Or when was NTP?

Conceptually, it's the difference between your wifi versus running a single fiber to each room in your house. The difference in bandwidth is multiple orders of magnitude.

This is never going to change because from a physical perspective free radio is a shared medium while each individual fiber (or wire) has its own private bandwidth.

Only a little bit. Just clicking around, a new Hawaii cable is supposed to have 24 Fiber Pairs and 18Tbit per Fiber Pair at the end of this year. If you lose several tbits of bandwidth, you're going to have a hard time making it up with satellite.

For small island countries and such, satellite capacity may be sufficient; and it is likely helpful for keeping international calling alive even if it's not sufficient for international data. But when you drop capacity by a factor of 1000, it's going to be super messy.

No. They're not setup to be a principal route between two nations and most satellite networks until very recently didn't even route messages through other satellites but instead retransmitted them to a ground station with access to hardline internet. Even Starlink mostly does this still because it's way cheaper and easier.

I never understand why questions like this get downvoted around here.

Only mildly. There's not huge amounts of dark capacity just sitting around waiting to take over so if a major fiber connection goes down the remainder will get congested with the extra capacity. It won't cascade like a power outage but the remaining lines will slow down.

The whole Internet was designed for precisely this use case. If there is an outage, the distributed system will try to find another path. No actual central point of failure. As you say, the single brick is hyperbolic. But yea, those sharks can certainly be disruptive at times.

Well that depends on how much traffic that cable was supporting, how much free capacity is available on other cables heading to the same area, how much additional latency the rerouting will add and how sensitive to latency the rerouted traffic is doesn't it?

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