Here's the truth: when you grow up, as you go through the various developmental stages, there are things which are vital to happen for proper psychological and cognitive development. For example, when you're very young it is absolutely vital that you are exposed to language. A lot of language. Of varying levels of complexity and formality. That's vital for the healthy development of the language centers of the brain and for early socializing. It must happen. If it does not, you see severe dysfunction as they get older.
This is basic psychological and cognitive development theory. It's taught in pretty basic level Psych courses. This is known science.
Socializing with adults, of various ages, both related to you and not related to you, in various social situations from social equals to authority figure, is one of those vital landmarks. And it comes up over and over and over during development. As a young child you must interact with adults, who care for you, so you can understand care and safety. And it gets more deep and more complicated as you develop.
Preteens and teens must interact with people older than them, significantly older, in various ways, up to and including casual friendly socializing as equals, or they will not develop properly. This is absolutely vital. Your ability to function in the real world socially depends on it.
We are fucking destroying our young people with this bullshit.
Source: Majored in Psychology with a focus on childhood development in university. This is what I went to school for.