I would say in particular lots of these people started doing "community slacks/discords" and then they realized that being able to produce podcast episodes doesn't make you a good community manager.
There's been specific drama with Relay and people around that extended universe as well, so lots of podcast hosts in that space are basically done with fan interaction.
I'm being a bit glib but I totally get it. If you have the choice to just walk away from dealing with CM stuff then it's a pretty nice proposition.