No, because after four years, I'd retire and live the rest of my life doing whatever I wanted whenever I wanted, starting my own projects on my own time to make any extra money or to simply satisfy my own interests.
You didn't say you were giving away a lottery ticket for open source. How much of the 350 is salary?
Somewhere between 170 and 225 is my guess. Still a lot of money but after taxes it's nowhere near retirement after 4 years. The stock could be worth something or nothing.. unless they are public or liquid I would discount that amount by 90%.
That salary is roughly $900,000, post-tax. If you couldn't retire off of that today, let alone use that money to live comfortably for a substantial amount of time, then I simply don't know what to tell you
That's why you do research beforehand about the company, the market, the product/service, and the people who are going to drive it forward. If those things together give you confidence in what the company is trying to do and their ability to achieve it, then you are taking what's called a "calculated risk" when you join them.
Existing companies also fail. You take similar risks when you join one of those as well.