OK, I'm gonna go ahead and go with the self-serving explanation that LW is mainly useful and enjoyable for people with 130+ IQ (25 percentile on LW survey) unless someone gives me a convincing reason to believe otherwise.
I know personally people with an IQ just above average who get a lot out of Less Wrong.
Nice to get this list-style article promoting LessWrong, Rationality Dojo, and Rationality: From AI to Zombies, as part of a series of strategies for growing mentally stronger, published on Lifehack, a very popular self-improvement website. It's part of my broader project of promoting rationality and effective altruism to a broad audience, Intentional Insights.
EDIT: To be clear, based on my exchange with gjm below, the article does not promote these heavily and links more to Intentional Insights. I was excited to be able to get links to LessWrong, Rationality Dojo, and Rationality: From AI to Zombies included in the Lifehack article, as previously editors had cut out such links. I pushed back against them this time, and made a case for including them as a way of growing mentally stronger, and thus was able to get them in.