I mostly lurk, too, but enjoy being around my fellow Lemmings.
The only decline I have seen as someone who mostly lurks is in conservatives who thought this was the next Voat. After the surge I saw an uptick in all kinds of people, and a lot of them I don’t mind seeing leave.
You don’t need this lil slice of the internet to be the “next big thing”, you just need a place to go to see the stuff you like.