You're assuming all late stage startups have ratchet clauses and using a single tech company (Square) to make your argument against joining any late stage start

You're assuming all late stage startups have ratchet clauses and using a single tech company (Square) to make your argument against joining any late stage startup. At a certain valuation, many late stage pre-IPO firms do start awarding RSUs vs. options (i.e. Facebook), which eliminates major downside risk to employees. If anything, I would be more weary of joining a mid-stage tech startup that is >$1 bil valuation with little revenue, nowhere close to an IPO, and still awarding options vs. RSUs. The inherent risks of other investor clauses (i.e. liquidation preferences) goes to 0 the closer a company is to an IPO.