Best I know of is /r/rational which focuses on rationalist writing, like Harry Potter and the Methods of Rationality, Worm, Ra (also by qntm), and a million other things.
As for meatspace, if you have a local LessWrong / rationalist adjacent meetup, those are usually full of people who read stuff like this.
As for meatspace, if you have a local LessWrong / rationalist adjacent meetup, those are usually full of people who read stuff like this.