I've got optical fibre to the home. I checked with Telstra, and I'd have to pay $5 more per month to get 25 Mbps or $20 to get 100 Mbps. So it's money rather than the NBN that's missing. I whinged that ADSL2 are getting the same speeds for less money and the response was that depends on the load. When a lot of people are connected the speed goes down, but the NBN conduit can carry a greatly increased volume of traffic with no loss of speed.
So- what I have works fine- I don't need 25 Mbps badly enough to pay another $5 per month.
I lived in PNG where 9600 kbps was bliss when you were lucky enough to get a connection.