I've frequently seen advice that equity offers dangled to prospective employees in a pre-public company should be valued at $0/share, because of the uncertainty of any opportunity to realize any value from them, the possibility of dilution before the company becomes public, etc.

If that advice is followed, it sort of naturally follows that there is no real rational reason to be particularly aggressive during equity negotiations, and that trading equity for other compensation is a smart move.

> I know a guy that took a CTO role at a company post-YC acceptance but pre-demo day for ~5%. I can't imagine what the rest of the crew is getting. Why even join a startup at that point?

Because the immediate pay and benefits, rather than the speculative equity gamble, is good, and because the work is what you want to be working on. And maybe you like the people/culture, too.