Comment 4 for bug 1910821

The dependency system in snapd is intentionally basic and it won't complain when uninstalling a dependency, because it has no way of knowing whether it's strictly required for the snap to work, or simply providing additional capabilities.

The fact that each snap ships everything they need is largely true, but for the exception of the platform snaps (such as gnome-3-28-1804) that contain a set of common libraries typically used by GNOME/GTK applications, which allows de-duplicating and consequently reducing the size of the snaps significantly.

If you're interested in the details, I suggest reading https://snapcraft.io/docs/content-interface.

I am not aware of a generic way to inspect a given snap's dependencies, other than installing it and observing which other content snaps get pulled in.