I'm genuinely glad for you that that was your experience as a child and parent, but it is not shared by many others, and for some the reality is horribly dark.
For some it was pretty much the worse thing that could have been inflicted on them.
Post Warning: don't read beyond this if unvarnished reality of how bad things can be is too much.
The "lifelong friendship, resilience and shared history" for mine, was not friendships, just being terrorized, bullied, injured, sexually assaulted, and for one, as well as all that, literal attempts made on their life requiring police protection to attend school.
For another of their cohort with learning difficulties it was to be lured away to be gang raped and have drain cleaner poured over them to try and destroy the forensic evidence afterwards. Their terrible screams as it burnt their organs where what brought attention to what was being done to them by their merciless school cohort peers, as a direct result of their "long term close association with peers in school."
Two others where simply murdered by their school cohort peers, but because it wasn't on the premises (one was outside) how they came to be the targets is simply ignored.
Could anyone possibly call this 'valuable socialization?' They are not alright, they are unlikely to ever be alright.
Mine, who had nothing to do with it, other than as a victim, is also not alright and holds survivors guilt for thinking if they had been listened to about the nature of those perpetrators, this might not have happened to this person, and also lives with the knowledge while they couldn't have been lured they could have been seized and bundled, and it could just as easily equally been them, as they had been threatened, survived a 'lower' sexual assault, and also seen as someone so low in their peer hierarchy as to be suitable for what was called 'downloading.' It has not served them well.
Some of those who did it where caught and are being punished by loss of their freedom, which brings no relief to those suffering the life long effects of that being their "long term close association with peers in school."
Others who sexually assaulted, manhandled, filmed and jeered, but where not considered the leaders, are already back out on the local streets playing their parts in more violence, and mine have to live alongside them constantly aware that they are known potential targets for them, as lifelong connected school peer association makes these dangerous violent people feel they 'own' them because of their shared history and knowledge of them.
They also happily try to face off and intimidate me as the mother of their prey and thus something to target. Their siblings, cousins, nieces, and nephews are all also potential targets by association to these 'shared histories.'
We can't move, and must suffer and try to be resilient to all this, while others gaily say as they don't have these consequences, it's all good and why wouldn't you welcome all comers to your childrens lives?
For one of mine their 'shared history' is being the survivor of those now serving life sentences in HMP, some for the above, others for gang murders, while they attempt resilience in living with the MH effects, physical scars, and what now look to be lifelong injuries inflicted by them, still causing them pain and disability. The 'shared history' haunts them daily.
That so called 'socialization' and how to try and recover from it and build a successful adult life despite it, has actually been very valuable to the children they have gone on to help working within the education system, and I am proud of them for using it in such a way, but the price paid for a childhood based on such lived experience was way, way, way, to high and the dark side of that 'valuable' coin is silent suffering still and periodic screams of terror at night as an adult.
Those younger than that one, have thankfully 'suffered the loss' of having none of those experiences, and just normal good friendships with mainly (but not exclusively) home or alternatively educated others, as well as some of those peers school siblings, and school attending members of clubs etc they have struck up friendships with, and a good education, and listen up to the older ones about how to stay out of the sphere of the violent criminals who have that supposedly 'valuable' 'shared school peer history' with them.