Our kids were born when we were in our late 30's with last one at ages 39. We had already established ourselves in our routines, jobs, friends, and family, so the kids really didn't have much of an impact. They didn't cost much since we already were settled in on where we lived. That is, we didn't move just because we had kids.
We had no problem socializing with younger parents and friends with kids the same age. Indeed, I think we had more time for volunteering at school and for example coaching lots of youth sports which was a real blast.
We had no problem socializing with child-free people and also older folks whose kids had already grown.
We turned out alright and I think are financially pretty much in the same place as without kids. Part of the reason is that we invested plenty before the kids came along and were nearly FI at that time. That money just kept growing/compounding just as the kids kept growing.
And I think the kids have turned out alright, too.
Things our kids did not get: cars, private school, new clothes. Things our kids did get: Scouts, music, art, sports, charitable work in thrift shops, travel with and without us. Once the kids are about 12, they pretty much have their own lives and can pretty much function with only mild contact with parents anyways. One can meet all requests for money with the response "Get a job." It works.
Anyways, I just don't believe in all the drama about child-free vs others. You are your own person. Do what you want.