At a big company, it doesn’t really matter if you work super hard or slack off. You’ll get paid roughly the same each month.
Life is short, spending all of it working at a job you dislike is a tragedy. A startup gives you a chance to avoid that.
Every answer is confined to the context within which it operates, and if you haven’t walked through the path that leads to that context, then the answer will either be completely irrelevant to you or it will cause confusion.