RSUs work because they're typically for already public companies. At vest, in the US, a percentage of shares are immediately sold to cover taxes. With illiqui

RSUs work because they're typically for already public companies. At vest, in the US, a percentage of shares are immediately sold to cover taxes. With illiquid stock - as in a startup - where there's no public market for it, and no one to sell it to, you can't really do that, and you're creating a tax problem for your employees. The company can pay those taxes on your behalf - but that's expensive when a startup is explicitly paying in stock because they need the cash to grow.