And if I've thought that, then how much more must people who've never been to university.
You're missing the point. Mos families (in general) wouldn't know an average points attained figure, or what it means, or how it relates to their own child, if it fell on them. For what it's worth, I don't know that figure either for (a) the courses I teach on or (b) the courses my children are on, and I've never heard them mentioned at open days, applicant days or anywhere else. I move in largely HE-working circles and no-one has mentioned them in regard to either their own courses or their children's courses, and they aren't mentioned in (for example) college education committees when we discuss applications. Outside MN obsessives, no-one looks at those. This is the only place I've seen them discussed.
About getting extra points, someone mentioned General Studies. Not sure if this is still offered at dd's school, but if it isn't, I'm contemplating even putting her in privately to get the extra 'free' UCAS points,
Why the hell would you do that? It's discounted by almost all selective universities. It might be accepted as part of a 240 point tariff by some recruiting universities, but even they are wise to it. I took it way back by walking into the exam room and answering the questions (and got an A, too) but these days it's close to worthless.
Why do you care what the achieved points score of other applicants is? Offers at selective universities are made in terms of three (exceptionally four, but it's extremely unusual, and usually relates to M/FM) A2 grades. The end. Only on MN would people obsess about UCAS points that no-one, outside the wonks in the very plush offices HESA occupy in Cheltenham, and a handful of obsessives who pore over the broadsheet league tables as though they mean something, cares about?