Xenia - I have to disagree with most of what you say too.
My DH teaches in a selective, reputable Private school. The school struggles to recruit decent teachers in some subjects, mainly maths and sciences. Sometimes, to employ a maths or science teacher who can teach the subject at A level, to Oxbridge candidates, they have to pass over the candidate who would make the 'best' teacher and take on the person who has the highest academic qualifications. Sometimes these people have been pushed out of Higher Education establishments and don't have a clue how to deal with teenagers. Some of them have no clue how to manage a classroom. Some of them have no clue how to transfer the information from their brain to the pupil's brain.
Boarding schools will recruit on the basis of what extra curricular activity the candidate can offer. "Used to play cricket for a county team? Fantastic. You'll do"
Some teachers join the private sector because they wouldn't be able to deal with children who misbehave and like you, beleive that children at Private schools don't ever attempt to mess around or disrupt a lesson.
Please, please get over this idea that private schools have better teachers than state schools. Both sectors have good and bad.
INSET days do exist in Private schools.
Not all private schools pay their staff more. A lot of the smaller ones don't.
"and a parent body which may be is easier to get on with" are you joking here?
and here?
"you don't have mixed ability in many private schools and most children are from homes without problems and no one with special needs."
The pastoral staff at DHs school are severely overworked with pupils who are self-harming, depressed, upset over their parents' break-up, to name a few. There is still mixed-ability and those who have some special educational needs.
It's still a good school with some lovely pupils, parents and teachers - but I imagine there are many state schools like that too.
My ex husband had taught in both sectors. I think I know a bit about it from the inside out over 20 years. I do think the teaching is better. You are allowed to be better because the children behave, you don't have mixed ability in many private schools and most children are from homes without problems and no one with special needs. It's easier to each in that environment.
Also some teachers are tempted by higher pay and in some cases free accommmodation in the private sector and free school fees so you do geta bit of a drain that way, teachers who want to work in schools with lakes and grounds and a parent body which may be is easier to get on with. SO a bit of a migration of good teachers to the private sector.
INSET days. I almost don't know what they are. My children's education is never interrupted for that kind of thing - another benefit in the private sector.