I'm neurodiverse and when I was pre-school age, my parents were concerned for me. There weren't many kids to play with in my neighbourhood, so I often played alone. They even put a classified ad in the newspaper to find playmates for me, but it didn't work. I've later learned that if kids don't get to play together at that crucial age, it will impair social learning later in life. Foundational brain circuitry for socialisation is formed at that time, and you can't fully fix it later.