To an extent, sure. That's more about keeping a community alive through a dry spell, though.

Digital communities can easily take years to build, that's not unusual at all. There's always lulls in that early period where the community is mostly dead, but there'll usually be 1-2 people just kinda keeping it on life support. Bones of the Moon has been doing that with our poetry sub for instance, if not for them, that sub would have died-died quite awhile ago. But since they (still, even) post there periodically, it winds up popping up on people's new or local feeds every once in awhile and reminding everyone it exists, and once in awhile someone else posts there.

That's the main reason I think people do it. Just kinda getting the community past that early period where most communities die out if left unassisted.