Copper can take quite a bit of abuse, the real issue you will find on your line will either be in the pit (Telstra trialled a program with a anti-water gel which had a reverse effect and corroded the copper connections). Or you have the issue of wiring within your house, even though household wiring is typically straightforward most houses in certain areas will have Optus and Telstra copper running into the house, how those are wired into the actual wall socket is another story as Telstra are only required to supply a working phone line if you sign up for TPG/Dodo or any other ISP that isn't Telstra. Sign up for Telstra and they ensure all wiring is nice and only distance/exchange conditions are a factor.