Sounds like you are trying to compare the many hundreds of miles (thousands?) of transmission cables needed to cope with the massive geographic change of generation sources to this ~20mi cable system.
There are many examples of how the UK is London-centric. This isn't one of them.
It sounds like sour grapes. London contributes nearly a third of the UKs tax income. It has a higher population than the whole of Scotland.
Not to mention that over ground wires are manifestly better in every dimension except for aesthetics.
This is a great example:
https://youtu.be/z-wQnWUhX5Y?si=qdqrpJ-zS7lh2J8Z
>contributes nearly a third of the UKs tax income.
Because it contains all of the financial services business that screw money out of all of the real businesses in the rest of the UK.