Having a 10 year exercise window on options helps quite a bit. In most cases there will either be a liquidity event within 10 years or (for companies that are successful but stay private longer than 10 years) the company will have multiple huge fundraising rounds and can allow early employees to cash out some shares in a secondary round.

To be fair the CEO should either eventually push for a liquidity event or should be open to allowing employees to sell shares on the secondary market.