That's true, @BigWoollyJumpers (about the smaller class sizes), and on that basis I think I was a bit harsh on the school local to me whose results had gone up so dramatically. They publish their A level results, subject by subject, 2018-20, on their website (A*-B, so a slightly different measure than the one in the table, but helpful nonetheless), and they are indeed v small numbers - most subject cohorts under 10 - so v hard to see a pattern.
In some subjects it looks like there's massive inflation between 2019 and 2020, but then 2018's results were higher still, so the picture is more complex than at first sight.
I suppose some inflation was inevitable last year, because lots of students are genuinely borderline and could absolutely go into an exam and get, say, a B or an A; and it wouldn't have been fair for schools to give them the lower grade when they hadn't had chance to prove themselves. Also schools knew there would be some external moderation.
I'm still really concerned about the total lack of consistency this year, and you can't help but wonder how widespread something like @SATSmadness' DD's experience is.