Still on Lemmy exclusively, but it's not my first time using a reddit alternative. This is normal. A large influx of users when reddit fucks up, but some slowly migrate back. Until reddit fucks up again. The problem is none of the alternatives survive long term.
The Fediverse has been around for a couple of years now and it's an open protocol rather than just a single organization, so I'm liking its odds better than most.
It's actually quite a good sign that Lemme is as stable as it is. It's not populated, but it's stable. That means that there's always something to come back to.