I think the difference with testing children now to when we were in school is that the tests now are designed to rank schools, not children. Formerly they were a useful tool for the teacher to know who was struggling and who needed more challenge; a means of encouraging pupils to do better.
Now there are detailed narrow targets that the government requires children to meet ("age-related expectations", as if they are a bunch of widgets)and if the data show that some children are not up to that expectation, the school risks downgrading in their OfSted. And then there are SATs...say no more.
I am a school governor and I watch the sort of stress that this puts teachers under - constant assessments, gathering of data etc., and I do not think that the stress experienced by children in school is unrelated to this. If your class has a number of children not meeting these expectations, then you are constantly striving to achieve these, even though the child may be better served by moving more at their own pace. Trying to balance the real needs of the child against government edicts is very hard indeed. Even though there is a line in the data for individual progress, this cuts no ice with OfSted, who can grade a school downwards on the basis of the raw data, even if the class has a high preponderance of special needs. And we all know, as I have said before, that children who have an of day (the dog died or whatever) and anxious children perform below their abilities - and yet the whole future of the school hangs on this.
No wonder the teachers are stressed - maybe the in-school mental health specialist should be for them. 