I would just point out re the specific case of Arthur, that in actuality noble is slightly wrong. No one did express concern about school closures and harms after he was murdered. It was only after the trial and the press coverage. If people had been so concerned following the murder, that might have noticed more that his school was not closed to him. I am not going to copy and paste assiduously all he info on these threads but there is a lot of misinformation on treads like this about social harms. I wouldn't go so far as to say it is disinformation, just opinion posted as fact, or ideas from Twitter or elsewhere on MN, repeated onwards with no due diligence.
Very few posters have commented on the primary issue of failings in social care provision , which is longstanding because school closures are a convenient stalking horse, it seems.
Sadly and troublingly, the murder rates of teenagers has gone up since lockdown ended, especially in London. I await the concern about this.