I lived in Silicon Valley for almost a decade, and stuck my fingers in the startup scene for awhile.

One thing I learned is that a some people running startups are "poker players." They run the company to keep up appearances: Their goal is to get more investment and eventually sell the business at a profit. (And then what the purchaser does is their business.)

There's nothing wrong with working for companies like this! You might not realize it going in; or the investors might see through the bluff and replace the leadership, creating a great job for you.

In contrast, you could join a business run by honest people, and they could sell out to a poker player who then ruins it. Or, more typically, the honest people turn out to be so-so business people and the business fails. (This is what happened when I tried to run a startup.)

At the end of the day, working for a startup always involves risk and the leadership structure will always change as the company grows, pivots, or fails.