I'm going to sound very self-centered and certainly not humble but when I was enrolled in mandatory education I was doing so under Tony Blair's Labour government. This government was elected under premises such as nationalisation and additionally "Education, Education, Education"[0]. As such no child was allowed to fail school.
This had the opposite affect in my primary school, instead of segregating the children who had difficulties learning or even the opposite- elevating children who were learning well; instead the entire class would slow to a crawl when it came time to do some form of verification that we're actually learning.
In many cases 'tests' would stop any possibility of new content being added to the class for months.
I was bored out of my mind and I'm sure I wasn't the only one. School is an absolute torturous prison when there's no stimulation of any kind; and they also wonder why you seek fulfillment by acting out.
Conversely, before my time there were English Grammar schools which were done away with, those output the most well educated people and were free for the public too. They just had very strict requirements for entry and you could be expelled for not keeping up. A stark contrast to the kids in my class who were unwilling or unable to allow the class to move forward as a unit.
Gah. I hated my childhood and I absolutely hated formal education because of this.