You have confirmed your are on Gfast ( see the observed speed date stamp ) , Gfast can be considered as FTTC on steroids just with the potential to offer much faster speed , it’s still a copper/fibre hybrid system, it was only ever available to some locations , and only offered in those locations to those on a short enough ‘line’ from the Gfast cabinet to get those faster speeds , ( Gfast cabinets are attached to the copper cabinet rather than remote from it like FTTC ) but apparently it can’t provide DV (telephony) like FTTC can , so that’s one reason why it’s no longer a product that’s sold and customers are managed off it and offered alternatives.
You ask what can be done , but the answer is not much , you could remain on it in the short term , TBH , I’m surprised you were offered any sort of Gfast renewal deal , renewal isn’t normally offered , only a change to FTTC ( which you were on previously and got maximum FTTC speed , 80Mb ) , trying to swap to another ISP that offers Gfast should also be unsuccessful.
As stated , whoever said that mid contract migration to FTTP (should it become available) can’t be done , is wrong , it’s a pretty normal upgrade path , so your choice is stick with BT Gfast in the short term , but appreciate that BT telephony can’t be provided with it after Jan2027, or swap to BT FTTC to keep telephony after Jan2027 , but both should enable you to migrate to BT FTTP should it become available at some point in the future.
