Hi all,
I worked at BT Labs in the early 1990s, and the technology did exist with blown fibre and jointing tools to do all the rollout. I also worked for Dr Cochrane.
BT was doing fibre local loop trials as well.
Whether it was TPON then and GPON now is not quite the point, because the single mode fibre has TeraHertz of bandwidth available in the 1300 and 1550nm windows.
This means that once you have put the fibres in the ground, especially with a Passive Optical Network (PON), you can get speed increases just by changing the terminal equipment and adding more wavelengths.
So the UK under the Duopoly Review in 1990 see
https://ieeexplore.ieee.org/document/181991 and trying have competition meant that the UK missed out in having fibre in the ground early.
We could have invented Openreach in the 1990s I think to share the fibres in the local loop between ISPs, but we didn't.
Cheers,
Tony