When I was at Cambridge our exams were only moderated by academics at UCL, Bristol etc, whose courses probably were of comparable standard. They weren’t moderated by ex polys which didn’t run a comparable degree course in any case (e.g similar courses at these universities had no language element whereas we had to do almost all our work in two original languages).
A belief that an Oxbridge degree is of the same standard as a degree at any other university requires the belief that students who get DDD at A level and go to a university who will accept them with those grades accelerate their progress so much at university that they catch up with and overtake students who go into Oxbridge with 4 A*s and end up with the same degree grade.
In the meantime Oxford and Cambridge, despite being so well resourced and requiring students to submit a huge number of essays etc compared to other universities, is achieving far lower outcomes for their students in the context of their starting point?
Sometimes that will be true and recruitment should allow for that. There will be very bright students who don’t reach their potential at A level. But on average if Oxbridge students are more academic going in they are probably more academic coming out.
My experience was that I was top of my school, top of law school, came top in professional exams but was completely average at Cambridge.
Of course being the person most able to succeed at Oxbridge doesn’t necessarily mean you’re the best candidate for the job. But sometimes academics are important and where you went to university is relevant information for assessing that.
My firm tried university blind recruitment for a bit alongside a written test. It significantly increased the number of Oxbridge students recruited so they scrapped it again.