This was requested many times now and the next release will include a more detailed view of what (apps, docker images, ...) occupies how much storage. Also there will be more detail about where those things are stored.
@nebulon Will it also show email disk usage? It’s not explicitly an app but it’d be very useful to understand how much disk space is used by email accounts and ideally digging deeper into which email accounts are consuming what amount of disk space.