strict church theory is that strict conservative churches grow while leniant liberal churches decline because of their austere demands of congregants. uu is declining, unity church is declining, united church of christ is declining, church of the prismatic light was a flash in the pan, mainline protestant churches are declining but evangelical, amish and mormon churches are all growing like kudzu. southern baptists got the lion share of congregants from the split northern baptists are like "american baptist who?" even though northern baptists are a lot less effed up.

but maybe it's not so bad we're small? why does liberal religion need a single institution to be big? i think the biggest u in uu isn't unitarian or universalist, it's unchurched, meaning folx that have the same beliefs as uu's but don't want to participate in organized religion. and i think uu's leniance is a virtue cos imo the difference between a religion and a cult is how they treat folx who left the faith, a test uu passes with flying colors. i think instead of concentrating on numbers for one religion uu should foster more interfaith stuff with like-hearted believers of all institutions and of none at all. it might even help uu get more folx since most people don't even know uu doesn't do dogma and that in this historically christian religion you can even be pagan (most pagans don't tell anyone they are pagan, let alone do so in a place that looks like a christian church).

tldr, love over numbers, many institutions over one