Wires out in the elements don’t just maintain themselves. Entropy is a law. Somebody has to pay to keep things working and that just isn’t going to happen.
It shouldn’t be dropping calls. It should still be on the PTSN. All digitization since the 1960s uses sampling that’s pretty good and hasn’t changed since. Once the old copper long lines went, everyone’s been using 300-3.4khz voice rang sampled 8000hz. It creates a very unique sound that everyone recognizes when they hear a human voice transmitted as such.
Now the end units, those have gotten trashy. The old landline handsets were solid and did a phenomenal job at receiving and transmitting the analog sound. Nowadays, the Chinese made junk phones have the smallest mic and earpiece possible. They use cheap radios which lower signal quality. All that affects quality of the call. I wish electronic places would have a kiosk where you can hear how each handset sounds akin to the televisions.
If you call quality sucks outside of hiss and crackle, I’d look at the handset. The main reason why I say that and not the equipment, outside of the digital switches, there’s been virtually no hardware changes in the digital equipment from the 1970s to 2000s. SLC96 led to Series 5 which led to Lightspan and DISCS which led to Tellabs 1000. Only a few generations of equipment all based on the same sampling and hardware design. All the same quality of reproduction.
Now, as to the failing landlines, it’s called “managed expectations”. The telcos want people to accept the quality of cell phones as a standard. The idea of a crisp and clean audio transmission that works 99.999% of the times you try and use it is “old fashioned”. Too expensive. Not enough profit.