At the time I write this, there are 385 groups within about 50 miles of my home. What I immediately notice are the numbers of language study and conversation groups, including Chinese, Japanese, German, French, Bulgarian, Spanish, and Italian. To learn a language, you have to use it, so these groups would no doubt be of great interest to some. There are large number of hobby groups, professional groups, and now especially many groups for those seeking a job.
I've never been much of a joiner, having only joined a handful of organizations, the most prominent being the Catholic Church (although technically I was already a member without knowing it!) But having subsequently studied the Social Doctrine of the Church, I now realize that small, local groupings are both to be expected — as a consequence of the natural laws of human nature — and are salutary insofar as they promote the good. Natural communities can be contrasted with the more modern notion of “intentional communities” which often act as group reinforcement of vices.
The Meetup groups representing religion and beliefs are particularly notable, especially by what is missing. Looking over the list of groups, I found that about thirty of these are New Age, nine are Protestant, and five are for adherents of the religion of atheism. Only two groups are Catholic, but that includes one which is explicitly heretical.
The sole Catholic Meetup group within 50 miles of my home is a scripture study group at Pauline Media in Crestwood.
Considering the fact that there are about 178 parishes within a fifty-mile radius of my home — and this only includes parishes in Missouri, there being more in Illinois — certainly minority religionists would be more likely to organize in this way. But wouldn't Catholics also want to organize their own groups?
The numbers of large pious and charitable Catholic lay organizations that were found in the past is quite astounding. This is quite a contrast to the common view nowadays that religion is something you do for an hour on Sunday, if there isn't a good game on television. Saint Louis still has many good lay-run organizations, but too often it is the same overworked and perhaps under-appreciated people who are involved in these.
I'm not saying that the Meetup website ought to be an instrument for promoting solidarity among Catholics, but it currently isn't. I know from experience that my own spiritual life suffers when I lack fellowship, and that is likely true for everyone whose sanctity is less than that of Saint Anthony of the Desert.