Someone had the idea to sort subs by the ones with the newest posts or comments, that'd be kind of cool.

I think browsing subs by new is the best way to find new stuff. But yeah popular is kind of borked because the subscription numbers don't mean all that much because we auto-subscribed everyone to every sub for the first year or two when we small, to make sure people wouldn't miss any content. But after we stopped that, the subscriber numbers remain, so maybe we need a new algorithm by which to sort popular