I agree with Monet.
I think Bonsoir also made the point upthread that the A level system allows students to drop too many subjects at 16, leading to a university population where knowledge areas are very cut off from each other, and cross fertilisation of ideas is hard to come by.
Apart altogether from the effect of this unwarranted early specialisation on PISA testing, the effects on career prospects of graduates who haven't done maths or science, or who haven't done serious, structured writing since age 16 can be very negative.
DD1 graduated from a leading US university and along the way did biology, chemistry and physics, Persian, French to the point of fluency in speaking and writing, calc 3, English Lit, fine arts, and on top of that her major, economics. DS, whose degree will be in biology, has a similar profile of courses, and DD2 is embarking on her own university career with two years of core courses to master in a variety of areas. No such thing as dropping maths or science or history or foreign languages for US students who want to go to university, and while there is certainly a huge disparity between top and bottom in US education, the top is very good indeed, and versatile, and able to make connections between different bodies of knowledge.
Interesting to see Ireland doing pretty well again on the PISA scores. especially reading. The Leaving Cert offers a broad curriculum and iirc three different areas of focus so that those interested in more vocational courses afterwards, or apprenticeships, can be served, while those who fall into the category of educationally at risk can also be served with a curriculum that focuses on their needs while raising their expectations and suggesting to them that education is useful and potentially rewarding, not an arena where they are set up to fail, which used to be the case for the lowest achieving group.
I think the biggest stumbling block in British education is the class system and its effect on what is available, school wise, for British children and the insidious effect on aspiration that the existence of such a wide range of schools and standards has. (Same goes for the US.) People who are used to the existence of vastly different opportunities and educational environments because they are living in it day in and day out all their lives don't see it for the monstrosity that it is.