@Fatredwitch
Someone has to come last. So someone will be humiliated every time. Chances are that it will be the same kids every time.
When I was at school, it would have been me. I had a lot of illness as a kid but I wasn't "unfit" in the sense of overweight or not getting any exercise. (The very long walk to and from school made sure of that!) I was just crap at PE. I was horribly aware that I was rubbish and so were other kids, who ridiculed me. I was crap at maths too but that wasn't a public activity, and children don't seem to regard uselessness at maths to be evidence that you are pathetic. They might even sympathise.
It feels bad enough to come last. To be further humiliated is downright cruel.
Last isn't necessarily humilating in itself.
Being last at parkrun having a chat with the tail waller, and getting praised for the effort. Not humiliating. There's an organisation that recognised the wider benefits of sporting particiation and celebrates the average finishing time getting slower as proof that a broader range of people are participating and benefiting and sees that as success.
Being the last one left on a school field while the PE teacher or classmates belittle you (teacher ignoring the wheezing and pained expression from shin splints and stitches "come on, you're not even trying" , classmates "lapped you! Lapped you twice! Lapped you three times!" Is humiliating.
Likewise being shit at team games is one thing, but never getting a properly inflated ball to practice with was never going to help (shocker, I can actually bounce a ball a bit if it's inflated!) And the routine of letting the school team players be captain and pick teams and every time seeing the look of horror as the numbers dwindled and the captain realising that she's going to get lumped with Bogroll by force of numbers. Then always getting the crappiest position, preferably substitute, or something inglorious like Wing Defence.
Being shit, I can handle, but the routine humiliation was down to the PE teachers to handle and in that kind of culture, there was no opportinity to make any progress.
My experience of PE on supply was that the general experience has improved, but clearly that's not universal.