90 days if you leave is deceptive and will lock you to the company unless you're independently wealthy. A less deceptive thing is a 7-10 year window if you leave, because that isn't "you forfeit your equity when you leave if you aren't already wealthy."

Equity pricing is also nonsense for many private companies. I was offered 1 million dollars in equity in a company 4 years ago assuming a multi-billion dollar valuation. It's unclear if the company has even achieved that valuation now, four years on. And they're still private.