Equity is granted alongside a commitment to stick with the effort through at least some ups and downs. The cliff forces that commitment. It is not just an alternate payment to cash for startups who want to keep payroll down.

If you want to work a series of short-term gigs, for equity, then just be a consultant and negotiate that as your payment. I've known people who have done that over the years, collecting lots of small bits of equity. They've been pleased with their results over time.