But in rural areas, Verizon, at the very least, is deliberately neglecting their copper, and not replacing it with fibre.

For people whose service degrades or stops working entirely, what do they offer instead?

Wireless. Which has much higher margins and much looser regulations around it.

At least for a while, Verizon was sending very strong signals that they wanted to get out of the wired connection business entirely, so they could do exclusively wireless contracts, including for your home broadband. (I don't know if that's still the case.)

This isn't a matter of "oh, it's really hard and really expensive for these multi-billion-dollar megacorporations to install wires going out to those rural areas!"

It's a matter of corporate greed, pure and simple.