Agree with the sentiment, but in reality, switching off copper in UFB areas right now would require all the affected premises to have fibre drops and the customers to have internal wiring/equipment and commercial arrangements to replace their current copper based services. I suspect that would be way more costly than occasional copper repairs. Also, turning off significant amounts of copper in 2020 might be optimistic (unfortunately) - might be driven by Spark PSTN upgrade??
Sounds the same as any other obsolete technology. Heard complaits when analog went away. Progress has to happen. Make it happen.