At our comp, the top three or four sets sit the higher paper (and that's with parallel sets, so eight classes in total) so there's definitely more access to maths higher than there was in my day, where only 1 and top of 2 sat the higher and everyone else intermediate.
I worried less about maths sets once I realised that.
That said, the higher paper can be very inaccessible to those who are not top set (even my DD1, who is bottom of top set, knows that the last two questions are not 'for her')- but you can get a pretty good mark with a quite low percentage, so it really is very different from what you might expect.
Their school only sets for maths and science, and science is just a set one with mixed ability below.
With assessments nearly over, DD2's friendship group in Year 9 are all terribly stressed about moving down a set. She is stressed too and no amount of me pointing out that she's not going to be there is stopping her worrying.
She's like Schrodinger's child at the moment - both focused on Year 10 at current school, even though she won't be staying, and Year 10 at new school. It has not escaped my notice that she has imported the new school's calendar into her phone and knows more about their masterclasses and trips than she does about her own!
I'm trying to help her to prioritise as she's crazy busy. She has the school musical, plus just had a zoom audition for musical at new school, and a concert at saturday school this weekend where she's playing two pieces. And D of E bronze next week.
Actually the thing she should probably be focusing on is Grade 8 flute next month, which really will be relevant next year, but when all your teachers talk about the focus being maths and science tests that isn't easy to work out. It was all less stressful when I was her age.