Having 8/9 GCSEs at the very best grades a student can achieve when doing a slightly smaller curriculum stands then in better stead for uni places and work etc than having done more subjects and got lower grades across the board.
I don't think anyone is advocating for lower grades as a desirable outcome. There are arguments for and against DD's school's approach of doing more across 3 years instead of fewer across 2 years. But 8 does seem restrictive for DC who could do well across the board in 9,10 or 11 subjects.
My own DC had to do eng X2, maths, triple or combined science, a language and a humanity. That left two free choices out of quite a range.
That's a total of 9 though. With a max of 8, they would only have had one choice. So they could only ever do one from art, music, drama, PE, design, a second language or a second humanity. They couldn't do both art and music, or music and a second language, or geography/history/RE, or economics/history/product design, or history/RE/art or both music and drama etc etc. Endless subject combinations that are appealing and make sense but are impossible.
At that school with 8 max, so one free choice, DD would have missed out on a second language, history, economics, drama and additional maths. She enjoyed and got a lot out of all of those. And she needed two of them to progress to the A levels she ended up doing.
I understand the argument that many DC are better off doing 8, but feel it's a shame when it's compulsory for those who could manage without such a narrow curriculum. Doing 9 or 10 also allows DC to really stand out if applying to universities who care about GCSEs.
And I get the "they only need 5" argument, but surely education is about a bit more than just the bare minimum required for the next stage.