I really wish someone built this - not just for fishing, for any activity, with the serious intention of forming long lasting friendships. Meetup is good for s

I really wish someone built this - not just for fishing, for any activity, with the serious intention of forming long lasting friendships. Meetup is good for specific activities, it is fun during the said activities. But it rarely lasts beyond those times. The only other avenue to forming good friendships seems to be volunteering. It would be awesome to have a place where making friends is primary objective, and everything else is secondary.