Just my two cents having had a little experience of getting some large scale electrical works done (bigger than a bank of superchargers, but still)
Planning approval is one thing, but DNO works and particularly wayleaves are another. You can have permission to build something, but the civils can be complex especially if landowners (who then know they have some power) want to make life difficult. Adopted streets may be OK because they are under the PUSWA (think that may now have been superseded), but there are sharks out there with their hands (fins?) out who can block infrastructure works and can hold the developers to ransom. If you need to drive a big truck past a field and that requires taking the fence down for an hour and rebuilding it, the fence owner can hold out for a fortune to give permission to do it. And tell their neighbour fence owners that they can also shake the money tree. So something seemingly simple can get complex and viciously expensive (way more than the engineering cost) very quickly, particularly in rural areas where a lot of the land is not owned by the local authority, and even more so if the landowners think there is a money pot they can milk (like a company owned by a prominent billionaire for example)...