Amazing result for asking thinking sand a question. To be fair though we already know that markets aren‘t solving all our problems and that externalities exist.
"Show me incentives, and I'll show you the outcome." The main product of these platforms is the attention they're selling to advertisers, so this is the only thing they optimize for. To change that, we need to change the business model. And I am happy that we see experiments in paid social networks (FC, Lens) that don't rely on ads.