It’s still not clear what you are asking, if the cabinet that serves your address hasn’t been upgraded with FTTC, then you could enquire with a Openreach if there are any plans for it to be done, or if there is any BDUK type scheme to improve speeds, or you could try and get a CFP ( community funded project ) up and running , where the gap between what OR are willing to spend and the actual cost of providing a cabinet is met by the community that will benefit.
As it’s an Openreach copper pair cabinet , then no other company can provide FTTC apart from OR, there is a product available to providers called sub loop unbundling, where this other company builds its own cabinet near the OR copper cabinet, and as it signs up customers , that customer D side cable pair is diverted into this third party cabinet, but it’s rarely used , as if it were economical viable then OR would have already done it
TBH , there may well be reasons why the cab that serves you hasn’t been done, perhaps too few customers would have a significant improvement, or perhaps getting power into a ‘fibre’ cab could be a problem.
