Big tech employs more people than startups, which means it's more likely for someone to get a job at big tech than a startup. It's just a law of numbers and has nothing to do with whether they're suited for startup life or big tech life.
In addition, in the US, foreign students who just graduated are more likely to get a job at big tech than startup because more big tech sponsor H1B/Green card than startups. And the fear/circumstances around losing your immigration status means more of them might opt for big-tech than startup
Google for example is much more rigorous with code reviews and code quality. They maintain a high % test coverage, continuous integration and delivery… etc. startups can’t maintain those same standards and move quickly. learn the rules before you break them.