The cables are near end of life and unlikely to be replaced at all, because the entirety of the copper network and its associated hardware is also near end of life.
Given the myriad forethought, procedures, standards, and quality checks with which AT&T handled their network (pre-divestiture) I'd bet a lot telco cable plant is nowhere near "end of life".
As someone who is well versed in that, its at the end of its practical life.
Both PIC and Lead Cable pinhole overtime, the life of areal (either PIC or Leaded) cable is 30-50 years, the life of buried cable is 50-90 - all of this cable exceeds that point, and must be replaced.
The phone switches that are connected to the cable are all near or over 40 years old, and closer to 45-50 years old in design, the spares pool is surprisingly healthy (because so many switches have been decommed) but the software that runs of these switches is also near end of life - and in the sustaining engineering phase of its lifecycle.
There may be a life for some copper cable, but it will be literally the last mile. Which is a lot smaller in scope than what we have now.
I mean, it was probably all in great shape 40 years ago. But 40 years of missed opportunities to replace cabling failing quality checks (if they were even done) is probably taking its toll. I know of many anecdotes of poor quality lines where trouble tickets end up with a pair swap which works for several months, and then you need to swap to another pair. There's only so many spare pairs, but the silver (lead?) lining is that enough customers leave that you can take their good pairs to serve the remaining customers. I've personally experienced the poor line records that mean connecting a new customer might disconnect an old customer, leading to a service call down the street.
For me as a phone nerd who would prefer to have a landline, but no longer have a good justification for it, and frankly I'm unsure if I even have a good drop anymore to my house (its not had service since 2010 - before I owned it).
I keep thinking I should reach out to AT&T and try to order services, but I just never quite get around to it.
Be prepared for sticker shock too. I recently set up my MIL with a CenturyLink landline here in WA, and it's $60/month. I could save a couple bucks a month if I declined long distance, but not many afaik. My California landline was less than $15/month with taxes when I turned it off, that was with no long distance and metered local calling (which was fine for me, I mostly wanted it for incoming calls and calls to toll free customer service).
It's just at "end of profitable life".