I honestly think that, generally, it does shake down.
If people never reciprocate invitations, then they eventually will dry up.
The reason people invite others to their house is because they like company, making and having friends, having a convivial time over food and maybe some wine. Or cake and coffee. Or takeaways. Whatever.
For the perennially reclusive, this is obviously just such a bizarre, foreign concept that you can’t get your heads around it.
I don’t mind hosting - in fact, I do enjoy it. But don’t think for a minute that the effort and cost is insignificant. It’s not.
But I do it, because I love getting together with my friends, and I love being invited back to their places.
Importantly, I also want my DC (who are also very social) growing up in the sorts of families DH and I grew up in - old friends coming and going, get-togethers, good times, memories.
I want them to be well-equipped to be good hosts, and guests, when they’re adults. And to get the social ‘rules’, as such.
If you resent the invitations from the more gregarious out there, don’t worry. They will soon dry up, and you can happily stay home, shutting out the world, enjoying your treasured privacy, into perpetuity....