Totally agree about the primary school stuff. My two are ages with your oldest. But, did you read the homework thread on here? OMG, the parents were shameless. They don't agree with it so their children just didn't do it! I think it's the link between school and home.
Do you think it's your school or all schools?
About your youngest. My oldest had unidentified difficulties. He was diagnosed dyspraxic by an OT. But he had a great primary teacher who allowed him to use a gigantic pencil he won at the fair to do his work as she could see it was more comfortable for him 😂. Great teacher.
He did get the extra time, though not scribes, for exams.
He is now, ironically, a secondary school teacher.
I do think children are being failed. For many reasons. First, the closure of special schools by Thatcher. Second, and most important imo, because children are being sent to school in nappies, can't use cutlery, swipe a book because they have never seen one, and have never been told "no" at the same time as never having been socialised.
I don't think the schools are at fault, they just have to pick up the pieces of poor parenting and, unfortunately, children like yours are caught up in the mess.