Re: Apples and oranges?
Almost 50 years ago, as part of my British Telecom Apprenticeship, I spent most of my first year with outside teams maintaining the copper network.
Most of the main trunk copper cables carried several hundred copper pairs and were pressurised (from the main exchange to help prevent water ingress) to a street cabinet (PCP or Primary Cross Connection Point) from there onwards a customers copper pair was carried over smaller grease filled copper cables via other street cabinets to the customers premises. Both types of cables would have underground joints (pressurised & grease filled) accessible via cable chambers in the footpath or carriageway.
Any water ingress, over time, started a chemical reaction with the water, electricity, copper conductors and crimps used to connect the copper pairs together. This usually resulted in a big bloom of chemical goo causing circuits to be degraded or to stop working.
An engineer needed to locate the faulty joint, using a combination of test equipment, cable spec charts and cable street plans. Once located the joint then needed to be opened (older lead/epoxy joints had to be cut/smashed), all copper pairs joints cut, cleaned & remade, then the joint resealed. These faults escalated in very wet weather which we get a lot of in the UK.
The other issue with copper, where there’s two pieces of very long copper separated by an insulator, is capacitance, to offset this we had to manually add inductance coils at the telephone exchanges, and if we needed to boost the signal we needed to manually wire in & setup amplifiers for individual circuits.
Also if a customer copper circuit needed to be rerouted because of a cable fault then this needed to be done by engineers in the field, at one or more cross-connection points, as well as engineers in the telephone exchange in the case of a trunk cable fault.
All very time consuming and expensive.
I left British Telecom in the late 80’s so my view is probably (hopefully) way out of date, but I have spent the last 40 years working in Telecoms/IT in the energy sector and fibre/IP* is the way forward, both for resilience, service monitoring and fault rectification. We've been aware of BT21CN and the impending end of analogue lines for at least 20 years, we migrated away from BT/Openreach copper for all our analogue lines many years ago.
*We have our own fibre/IP network and only use BT/Openreach as a last resort.
Copper has done it’s job, but it’s had it day, technology is moving on. Sorry.