For me, kids have had a “filtering” effect. Where previously I had a lot of friends (including shallow ones), having less time and being less flexible in general compressed my circle of friends to just a few people with whom I share both a deeper connection and a mutual understanding that the pressures of life sometimes get between us, and that’s ok. And as another commenter mentioned, kids do grow older…
You might confirm or not. As far as I observe it, the "deeper connection" is virtually always with other parents. And this is exactly the connection. Without children, it's neither possible nor attractive to be one of these persons.