Just count yourself lucky that you don't have an Exchange Only (EO) line, that doesn't have a cabinet and runs directly to the exchange.. I'm in Whitechapel (Zone 1) and get 8/1
There is an ongoing programme to upgrade EO lines to have their mini-cabinet so they can get vDSL. You are an inadvertent casualty of "unbundling". To promote competition the Exchange is allowed to have equipment from other providers in it (most exchanges have only one or two other FTTC providers, many have none) and that _could_ be ADSL and so the interference from VDSL _could_ break that, violating the unbundling rules, so, they just don't offer VDSL.
It would be technically easy to give you VDSL, it would just break a rule that was put in place to ensure competition for ADSL service, which you now don't care about because even that close to the Exchange it's only giving you 8/1
I have a friend who lives in a small market town in the North on an exchange only line, he gets 2/0.5. Most of his neighbours can get vDSL too, poor bastard.
He uses a 4G router with a Three unlimited SIM.
He has both connected because we do a lot of FPS PC gaming and the latency on 4G is too poor to game so he switches to his ADSL connection to play games and then uses 4G to download/stream.
It would be technically easy to give you VDSL, it would just break a rule that was put in place to ensure competition for ADSL service, which you now don't care about because even that close to the Exchange it's only giving you 8/1