Hmm, I didn't realise that's why the rollout was stopped. (Which doesn't really make sense as a given reason anyway because wouldn't the fibre just have become part of openreach anyway.
So I think new technology is generated through research funding, either public sector (universities) or R&D depts in private companies (today companies like Apple, previously old school companies like pre-Welch GE). I guess BT was more like the latter, except state owned.
In telecoms there's also a universal service obligation, which does not make economic sense when driven purely by profit motive. Cost of rolling out fiber to a small village will probably never be recouped. Thats why FTTH w/ Virgin Broadband was only available in cities for a long time, and expensive.
In the US where telecoms have regulatory capture, and no public access telecom network, you see stories of rural communities trying to fund their own infra. It's expensive.
Cost of rollout and universal service can be helped by rolling out at scale, building the factories, reducing unit price etc.
So all this together....
I think private companies _can_ have the foresight to do this kind of forward planning...
But a big nationwide rollout of a public good? Where is their financial incentive? They would provide an environment for the acceleration of future commerce and technological development. But if they don't make money from it, why would they?
BT was deep into preparations for a nationwide fiber rollout at the time of privatisation in the early 80s. The project was cancelled, the fledgling factories equipment and expertise were instead exported to South Korea, enabling their widespread fiber penetrance.
That delayed fiber rollout in the UK by decades.
Was that a success? Could be they were too early to justify the cost?
But without someone pushing ahead, who develops the technology?
But it is not super reliable or friendly.
[1] https://github.com/spieglt/FlyingCarpet