That is one of the worst arguments for public schooling ever. Throwing kids into groups in which they have no chance of ever knowing every member of the group creates stress and causes withdrawal; our instincts never developed to be in community groups of over about 200. The extroverted kids will form social networks, while the introverts struggle and may never form connections. Plus, the extroverts will often pick victims (isolated introverts, of course) and harass them mercilessly; the forms of harassment have become much more sophisticated because of technology. Liberal society only notices bullying when the victim is from a protected class, e.g. LGBTQMRXIS, but utterly ignores other victims. And being a victim of bullying creates a huge risk factor for suicide, along with a host of other psychological problems.
No, you do not send kids to school for socialization. You send them there to learn social pathologies. If you want them to learn social skills, you send them to play in small groups, for instance, at a local neighborhood park.
Excellent points. The impersonality and cliquishness of large public schools - along with bullying - are well-known problems, along with diminishing academic standards.
Correct. Most children make few close friends at school because the children are drawn from a relatively large area. Most of the other students remain strangers with - at most - a vaguely familiar face. Most of your friends tend to be children from your own neighborhood, who - as you say - you associate with in small groups, and who you interact with even if you don’t go to the same school.