Centralized package repositories like the one provided by canonical have similar limitations to the Mac App Store, you need to get your app reviewed, you need to push updates to each platform where you distribute your app and in exchange you get visibility.

I'd argue that installing and updating apps on MacOS is simpler than on Linux distros because most apps have built-in auto-updates (or you can just drag the app to the applications folder) instead of having to rely on snap / apt / insert your package manager which may a lot of outdated and unmaintained packages and apps.