My wife & I have an 18-year-old son. He started university in September, studying medicine. There he met this 41-year-old man - a classmate, and they became really good friends. This man has just started university now at this age because apparently he was born poor and in the first half of his life was focused on making money, but medicine is a dream of his. Son has always been an introverted, shy, socially awkward kid with little friends, but now goes out often. Honestly my wife & I are uncomfortable, and we can’t help but side eye the dude.
I went to community college for my first two years and only had adult friends. It was exactly what I needed at the time because they shared their life experience with me and it was immensely helpful in making my own good decisions. Now in my 40s my husband and I are the older friends in our game group who do the same for our 20-something friends. We even convinced one of them to get his GED and had a big celebration for him once he got it when his own family blew him off over it. You have to make your own community where you can and older people outside of family have value too.