This assumes that anyone has maintained the 48V infrastructure, which doesn’t seem like something that will be feasible considering the insignificant quantity of customers using true copper landline service.

The other problem with customers preferring not to have landlines is that by the time they need them, it’s too late to convince them to buy a traditional telephone and plug it in. You are likely to be nursing home age if you still prefer having a landline. You can have amazing infrastructure but if nobody uses it, it’s useless.

What we really have now is cellular sites with their own infrastructure aiming to keep them operational during power outages.

Then we’ve also got various satellite services that are growing in capabilities day by day, and are built in to common devices like iPhones as an SOS method.

I’m not in the UK but my house was built relatively recently and it doesn’t have any telephone jacks. The theoretical benefits of a landline are entirely theoretical. The ship has thoroughly sailed.