WRT some points on this thread. Early on, some parents ask what they should do.
I'd say, step one is contact your MP and telling them to put pressure on Gillian Keegan to come back to the negotiating table. If they are Tories, tell them that schools and education are a top priority for you, and you will not vote for them (even if you never would) if the situation in schools does not improve. If they're not in a very safe seat, it might make them think.
In terms of services schools are expected to provide- I do think we are providing way more social support, way more mental health support, supporting students who can't get a diagnosis of SEN, supporting those with significant SEN or health needs who would have had more specialist input in the past. And yes, increasingly, effectively being asked to do the job of the police by dealing with incidents, up to and including sexual assault, which happened outside of school time. Our local police are very often not interested.
The thing about schools is that we see (most) students on a regular basis. We are the one service that won't allow students to fall through the cracks, because they are always here, and if they are hungry, if they don't know where they are going to sleep tonight, if they are in trouble, if they are struggling with their mental health... they come to us, because they know we won't turn them away- even when all other services are ignoring them. The increase in social problems, due to the CoL crisis is picked up by schools, and so many other services have been cut to the bone.
Finally, in terms of behaviour-
It is worse than when I started teaching, and so much worse than when I left school (00s). The school I teach in now is very similar to the school I went to- arguably a "nicer" catchment in some ways. When I was at school, the idea of swearing at a member of staff was pretty extreme- it happened, but it was rare. Completely refusing to do what a teacher asked was rare. Fights were rare. Assaults against staff were unheard of. There was one serious assault between students the whole time I was at school. All of these things happened in my school in the last half term- some multiple times.
I am not against the idea that good relationships between staff and students improve behaviour. I believe it's true (but it needs to be alongside consistent boundaries and a clear behaviour system)- BUT what I don't believe is that there is any shortcut to forming relationships, particularly with students who have difficult home lives etc. It takes time. At my previous school, I had good relationships with some really tricky Y11 boys - but it took teaching them from Y9 to get there. I don't believe there was a shortcut.
When staff turnover is high, these relationships can't form, and then your only option is punative behaviour systems, because they're the only thing that keeps the majority of students safe and able to learn.
But when behaviour is poor, staff turnover will be high. So it's a vicious cycle.