Admins are quite active behind the scenes (the report queue is constantly being handled).
Personally, I have stopped posting on my main account for the most part, as my identity is more or less public information, and this has been used in some attacks against me. So for regular posting, I am using a more anonymous alt account. But the instance is definitely not abandoned.
Just quickly popping in to point out that this is not an innocent question. The OP of this post has been banned and warned repeatedly over several instances for extreme transphobic behaviour, and is now in charge of the conservative community on lemm.ee.
As you can see, this post comes 5 hours before an extremely transphobic post they themselves submitted, was removed by the admins. I complained well prior to that action, on their forums, complete with receipts, and had my comments deleted and was given a one day ban for "harassing the mods". By posting their history of being banned for the kind of post they had just made.
They were well aware of their actions. They were checking to see if they could get away with it, and were dearly hoping the admins were sleeping.
Looking at one of Sunaurus' last comments: https://lemm.ee/comment/3660174 , dealing with the shitheads wasn't treating him well. I hope he's OK and at least somewhat still believes in the idea of this place.
The reason I ended up settling on this instance was because of Sunaurus' level-headed leadership. I guess there's only so much one can do to insulate themselves from the muck, though. Most I've ever had to moderate was 300 active members, and that was fortunately without any major issues like the shitfit over Hexbear. I can't imagine the quantity of garbage that flows uphill.