I can state, categorically, that in my subject at least, exams have NOT been dumbed down and in fact are harder than the O or A levels we took. I am an examiner in this subject in addition to being a teacher of it.
On top of this, in my subject, teaching required knowledge for the exam is exceedingly boring, unlike the pre Govian exams. This is borne out in a reduction of students taking A level in this subject.
Finally, as both an overseas and UK teacher, A Levels are THE gold standard. More than International Baccalaureate. I wish we didn't have the furore over exam quality every year. It's based on a rose tinted spectacled/arrogant view of the past and devalues the exceptionally hard work some students put in.