“Bigger” is a bit missleading here. Really bigger updates obviously require a major version bump to signify to users that there is potential stability or breakage issues expected.

But “bigger” in the other sense i.e. meaning slower, means that there was more time for people to run pre-release versions if they are adventurous and thus there is better testing.

Of course this assumes that there are actual beta testers and that it is easy to do so by creating such beta releases.