Yes for sure, it isn't sudden. I think right after college people "settle down" at different times. Some marry early, some later. Marriage and kids are huge tim

Yes for sure, it isn't sudden. I think right after college people "settle down" at different times. Some marry early, some later. Marriage and kids are huge time sinks. By 30 many are married. The more that are married means less time for friends, and slowly those "groups" wither away to the most important.