These aren't mutually exclusive, unless you have an extremely narrow definition of a startup: https://techcrunch.com/2025/02/20/38-startups-have-become-un...

You're right, but a startup has priorities a billion dollar company doesn't.

And a billion dollar company can spend more time on min/max than a startup that is trying to get to PMF.

A billion dollar company isn't invincible, you can still be zeroed out by an unfavorable market. https://en.wikipedia.org/wiki/Exodus_Communications

In 2025 dollars their peak would have been $59.5B. To wit, this is roughly what Doordash is worth today, and that's a top-5 YC company. It died 9 months later.