Source tree on rootproject vs a module

When I create a project via New Project -> Kotlin Multiplatform -> Library then gradle source trees are added dicrectly to rootProject

This is a bit confusing, Why not a module? if I create a multiplatform app from Android Studio then there is a module called shared, which gets included in other targets.

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Lets say I want to add a completely new module, which should have dependency to those source trees, then I can add them like implementation(rootProject). Is this a right approach? What if in future I decide to divide commonMain into different feature modules?