I really don't think that needs explaining, particularly for someone who proclaims to be familiar with this sort of thing but I'll bite. It's just not practical to individually eyeball 27 million households to check if their parking is suitable for a charge point.
As I already mentioned, you don't need to personally eyeball it, as you can do it very accurately with geospatial analysis software. Given that we do exactly this on a frequent basis, I'd again ask why they're all still extrapolating and estimating... and why their estimates vary so widely between each other.
I've yet to see anything from you or Skoda to back up your assertions that most car drivers do not have off street parking for at least one car in the face of all other signs pointing in the other direction.
I can't speak as to Skoda's assertions, as I haven't been following that part of the thread, but I don't think it has anything to do with mine... His seems to be more about the need to massively upgrade and invest in infrastructure, which is what several of your own linked reports also said, except he doesn't think it's as likely to happen as the EV advocates seem to hope. I'm inclined to agree, purely based on my experiences of working with and within the utilities industries.
But speaking of mine - My assertion is nothing to do with what I believe, but more challenging your proclamation of "fact", which appears to be based on nothing more than the
loosest possible definition of "most" being an extremely general 'more than 50%'... and that this is still stated as being those households "having, or with the
potential to have" off-street parking, with particular attention directed to the fact that the 'potential' for something is not the same as it actually being so, nor any indication of future likelihood, and thus why I'd further question such inclusions in these estimatory surveys of varying discrepancies. At best, these very general assessments seem to point more to a rough average in the mid-60s, percentage-wise.
I also note that, just as I mentioned beforehand, one of your articles links to an RAC Foundation breakdown of available off-street parking by Local Authority District, in which it has Reading with only 48% availability. So like I said, not even a loosest-possibly defined majority here, and we're not the only such town.
https://www.racfoundation.org/wp-content/uploads/standing_still_off_street_parking_by_LA_A-Z.pdf