I think while the general communities have made it, a lot of niche communities failed to attract enough population to keep on generating more content. As an example, just search for the “Imaginary” series of landscape art communities on the Fediverse (eg. ImaginaryVistas). Many of them don’t have any recent posts or 1 post per days or weeks. That’s not enough to keep people invested. Even the largest digital art community is still mostly carried by 1 person.
Much further back… Abraham Lincoln was a Republican. The party was founded on anti- slavery. The current party has nothing to do with the original party.