This. My wife and I built our social life when we moved countries, and we had a group of friends that we'd meet every week or two. But only when we invited them. No-one else in the group ever organised anything. It got really tiring. We could not get anyone else to organise a meet, they always had reasons why they couldn't organise one (but could turn up to it fine). We tried a bunch of things, but nothing worked - if we didn't organise it, it didn't happen. We ended up moving away and the whole social group collapsed and stopped meeting.
I think some people are just the center of gravity, and that particular friend circle revolves around them. Before COVID, we had a friend group that would hang out fairly regularly. Once I left (for a job, not fleeing the city), none of them hung out without me. Everyone was friendly with each other, but everyone also had their own lives going on with their own friends and other circles. While I was the glue for that circle, it wasn't like everyone just stayed at home having pity parties when I wasn't around.
My anecdote might have limited relevance here, but I think it's something worth considering.
Do any of those friends organise anything for any of their other friend groups?
I get the feeling that some people organise, while most people don't. I haven't seen the situation where a person organises stuff for one group, but not for another group. It always tends to be the same people doing the organising for all their friends. At least that's what I've observed, I'd welcome any other observations.
That attitude, the some people are leeches, to me is part of the problem. If you go in with the expectation that others owe you something or they're bad people, you're only going to be going down the path of not doing it.
