Also if the cabinet to the exchange is already fibre optic wouldn’t that be a good place to connect and extend the fibre cables to everyone’s streets?
No, there's only a few fibres needed at the FTTC cabinet, and that's including a couple spares.
When the FTTC rollout was starting they placed Aggregation Nodes in the ground.
These nodes are designed for... Aggregating fibre.
A single aggregation Node feeds 3 or 4 cabinets on average.
The fibre for FTTP doesn't come
direct from the exchange. It's already as far as the aggregation Node, which may or may not be near your cabinet.
You can't just connect and extend in to a fibre either.
Each PON needs its own dedicated fibre.
The fibre is brought from the Aggregation Node to your local telegraph pole or underground chamber.
At this point you can order FTTP.
Then they only need to run fibre from outside your house (from pole or chamber) to inside
your house.