> My wife and I's friends have basically vanished from our lives, they have zero initiative or interest in coming over to see the kids or help in any way

I completely believe that’s been your experience, but want to highlight that his is a difficult asymmetry in these friendships. I in no way mean to imply that the below is the experience your friends had with you, just that the challenges are not one-way.

In my own circle, my wife and I have often felt like it was our friends with kids who vanished. We knew they were busy, we kept extending invites or asking for time. Things often didn't work especially as new parents are figuring their lives out, things are changing all the time, etc. We'd meet up here and there, but it was - necessarily - always on their terms. And so of course, our outreach tapered down incrementally but consistently.

But I do wonder: do they feel we detached from them, or do they have any inkling that we feel they detached from us? We've discussed it with one couple who we were always closer to, but it doesn't feel an appropriate topic to resurface uninvited at any given moment.