Google's equity is cash. Ziplines is not real. I would much rather work at Zipline but given the delta in cost I would rather not forgo $1-200K a year to work there given bay area housing costs.
Each person has their own risk tolerance. Not taking on any risk at all is certainly safe, but also limiting. I've always taken a probabilistic "expected value" approach when weighing financial decisions, and so far it's worked out favorably. I don't think it's fair to conflate liquidity with reality. My equity in Zipline is real enough, at least to the Internal Revenue Service!