Depends a lot what you compare fiber to.

mobile broadband can easily have 20-30 ms latency to the ISP.

DSL is often 10-20 ms. Coax is in the same range, depending ont he provider.

Fiber is usually 1-3 ms.

I don't understand why rural is relevant to the latency I posted?

Very anecdotal but I just switched from cable to fibre and latency significantly reduced, form like 20-30ms to 5ms.