While I agree with you, there is absolutely no reason why BTOR couldn't drop / remove the copper from the cab to the exchange.
Line testing? Everyone seems to forget the O&M activities...
That seems to be the main reason given for why SOGEA still needs a copper E-side: that the way to perform a copper test on the D-side needs a physical connection through the E-side.
And what about LLU operators? They are worried enough about stranded assets that they won't let LR-VDSL go ahead, so there's no chance for a generic removal of the right to connect over copper to their exchange-based equipment.
For the phone they could modify the cabs to include FVA and use the copper from the cab to the home. And for ADSL They could drop that and provide a similar speed via FTTC at the same price.
How about the issue of capacity?
Some FTTC DSLAMs would need to be 2x or 3x bigger, if every line was going to be forced onto them.
Oh, and with every line on VDSL2 on the FTTC DSLAM, you just increased the issue of crosstalk. That might require vectoring to be added to all these larger DSLAMs too.
So it is possible, but doesn't mean it will happen though.
Absolutely, it is possible. But we're a long way off a concerted effort to do this.
I do see a gradual swap to SOGEA over the time to 2025, and rather than naked DSL, I see this as being offered with FVA. Doing this allows BT to gradually degrade the capacity of their System-X and System-Y exchanges, as failures happen (they'll essentially fill their own "spares" store).
In the same timespan, we'll see an increase in capacity in the access network, either through G.Fast nodes, or through some gradual FTTP rollouts. Eventually, there'll be enough capacity out there, and (eventually too) Sky/TalkTalk will figure the need to decommission their ADSL kit. *Then* we'll see a shift.