It should also be noted that MacOS, iOS, iPadOS, WatchOS, & TvOS are all built on the same core. So any new feature or bug fix to any one OS may well involve a change in that core code thus requiring the change to be tested in each of the other venues to be sure it does not create unexpected problems in those environments and thereby triggers an update of all the variations. So, for example, a MacOS update could potentially be triggered by the addition of support for Apple's new Fitness app in iOS and WatchOS. (It is rumored that Apple will introduce a new Apple TV this spring with support for games and gaming controllers which mightl require tweaks to the core and trigger another round of updates to all the OS varieties.) It should be noted however that these updates are also a good opportunity to sneak in bug fixes and security patches unique to particular devices as well.
The point is a MacOS, iOS, iPadOS, WatchOS, or TvOS update does not necessarily imply there were significant or minor problems unless you have access to the complete developer release notes and even then you might not comprehend the magnitude of change in any given release if it was not in your specific area of knowledge/expertise.
