The undersea cables actually connecting the entire internet. Sometimes sharks just take a bite of them, they're reasonable well protected but it's enough damage to cause outages and disruptions.
It's the single pin under everything because there are a limited number of those cables especially in some regions so a single shark can take out the entire internet for some countries.
I feel like having them as a single brick is a bit hyperbolic, since undersea cables are pretty redundant in most of the world. Get rid of one and traffic just routes around it. Ships have been routinely destroying cables in the Gulf of Finland and the Baltic Sea in the past couple of years without causing significant disruptions.
Do satellite networks not move the needle in terms of capacity/reliability now?