The NBN Co might use an old fashioned mirror to find some of the cause of this problem.
The NBN Co needs to consider a few more facts. It doesn’t matter what the original assumptions were. The NBN Co decided to start back filling outer urban areas and rural communities with FW adding substantially to the FW customer base.
Many of these areas have ADSL coverage. The NBN Co could reasonably expect all with ADSL in these areas to switch or loose internet. Easy number to look up for them. Add to these the customers in the same service areas too far out to get ADSL who were now able to connect and have done so!
That’s aside from the unrealistic original assumption of a low take up rate that said 4 out 5 homes don’t want the internet.
This was all done to save expense extending the fibre/fixed line solution. And load up the FW network to improve it’s income potential.