As other posters have said, the issue is whether the rules are reasonable and sensible, and the sanctions are proportionate, @Teachingquestion.
I would rather a school concentrated on the issues that can really impact the children's learning, rather than petty rules. So, for example, I'd rather that the uniform rules had some flexibility in them, but the children were taught to behave in class, and disruptive behaviour was firmly dealt with.
My dses went to a secondary school that had, in my opinion, a very sensible uniform policy - black trousers or skirts, white shirts, school tie, and a choice of black zip up sweatshirt/cardigan/v-neck jumper - the only stipulation was that the knot of the tie had to be visible - so a zipped up sweatshirt had to have the zip lowered to show the knot of the tie. PE kit was shorts and t-shirts/track suit for winter - the only rule was no football colours/strips.
We had moved to the area, and ds1 and ds2 had been in selective grammar schools with very strict uniform policies - that cost the parents an absolute fortune, so we were very happy with the new school's policies.
The reason that I have seen given for strict uniform rules is that it creates high standards that help to improve general behaviour - if the kids have pride in their appearance, they're likely to behave better - but in my experience, the behaviour at the schools with the strict policies, and at the school with the more flexible policy were pretty similar. The two boys who moved from the strict grammar schools carried on achieving academically at the same level they'd been at in their previous schools, and ds3, who did all of his secondary education at the more flexible school, also did really well academically.