One potential downside is that the subscriber number actually is just the people who subscribe to that community from your instance and not all instances. This will need a patch from Lemmy itself to fix. As it is it’s a bit misleading, like maybe one Android community seems bigger, but actually it’s just more people from the instance you are using, and not more people overall - there is no current way to know.

Second. Like the idea. Here is how wefwef/Voyager does it.

Ability to sort by subscriber count too would be nice.

there is a feature request for this on GitHub