I’m honestly surprised the low voltage cable lasted as long as it did.

I'm surprised too, but depending on what equipment is in the house the neutral can see much less current than the hot. US residential is usually split phase power, so 240 is provided by two out of phase 120 wires. Since most large loads (air conditioner, stove, oven, etc) use 240v they don't put a load on the neutral. The 120v devices put a load on the neutral but if the house is well wired they cancel each other out since half are on one leg of the 120 and half on the other. From the power service view they act like one large 240v device.

I'm going to be honest: until my neutral line was severed by a tree falling on the line -- while not fully severing my power -- I thought the bare metal wire was just there to support the power lines physically.