How old are you? I went to a posh boarding school in the early 2000s and there were many things wrong with it, but it wasn't nearly as brutal as you describe. Other pupils did unpleasant things to me (and I to them) but it was mostly just testosterone-fueled adolescent stupidity that I'm sure happens at less privileged schools too.
As I understand it, the Childrens Act of 1989 had a huge effect on how these places were run. It took a while for the law to filter out into practice so people who went to private / boarding / posh state schools in the 90s experienced a gradually toned down version.
I suspect that in the early years, when physical punishment was banned, the psychological stuff amped up a bit.
Even at a state school in the 90s, some things we thought were normal would be shocking and absolutely a child protection issue these days.
I was surprised to learn recently that corporal punishment wasn't banned in British state schools until 1987, and in private schools until 1999.
"Surprised" because by 1999 I'd been attending a British private school for several years and corporal punishment certainly didn't exist at my school, or at any school I knew about. Apparently it was permitted on paper though. I'm not sure how common it still was, if it existed at all.
In any case, the worst treatment I received at school was never from the staff and always from the other boys. I can definitely think of some behaviour I saw from pupils back in the day that I'm sure wouldn't be tolerated for a second these days.
In the US, I have relatives that were locked in closets by teachers and had their knuckles rapped for using their left hands.
A combination of factors (cameras and modern communications systems being two significant ones) have shone a lot of light into what used to be very dark corners.
I went to school from in Scotland about 1970 to 1983 - without much difficulty I can think of quite a few situations that I would hope would result in sacking and criminal charges these days.
Being a bright kid and usually "teachers pet" I didn't get too much abuse directly but I can remember one poor guy who clearly had learning difficulties getting his face smashed repeatedly slammed into the blackboard by a teacher - we were about 6 at the time. :-(
40. I had the misfortune of getting the worst of both worlds.
Prep school, from 6-12 was a nightmarish place where it was still 1935 - masters from my time there are now in prison with good reason. Corporal punishment was a daily fact of life - a caning was a relief compared to some of the options.
Secondary school - in the shell, we were made to fag, and prefects were permitted to issue corporal punishment, which happened frequently. Nothing testosterone-fuelled about it - cold and calculating. “You will convene at 5am at the oaks in full uniform”, and then whatever horrors they could come up with. Ski squats that would go on for hours. Standing outside at night in soaked clothing. The occasional good old fashioned beating. In my remove year it was decided that shells were too young for the heavy duty of fagging and it could be damaging to them - so the removes did it. In the fifth form they abandoned fagging and replaced it with “fifth form house duties”.
You learned to live under utterly arbitrary rules.
By the time we were in the sixth, duties were phased out and replaced with hired staff, and corporal punishment - in fact any prefect-meted punishment whatsoever - was banned in response to an incident involving cricket bats that resulted in a pupil being hospitalised for quite some time. Well, that and the law finally mandated it.
My kid brother went there, starting a year after I left, and had a markedly different experience. En-suite showers! We had a frigid communal shower for my first two years, never mind en-suite. It’s like we went there a century apart.
That all said, by the time I was at secondary school it was all old hat - there was a marked difference between the boys who started boarding with secondary school and those who had been through prep school - we were the wise old hands, the lifers, the ones who knew the grift. Prep school, I find it hard to talk about.
Turns out there’s a term for this stuff - “Boarding School Syndrome”.
I imagine things were worse in the past though, see e.g. the notorious practice of "fagging" https://en.m.wikipedia.org/wiki/Fagging