And the fact that you can run the indexing and visualization in separate passes is extremely useful, especially for E.g. large network file systems that are slow to index.
I like, I've been working on a faster parallel scanner written in go for the really large filesystems, in my env it's around 10x faster. In any case I find the scan -> database which the client can view quickly very useful.
Also note that there's text based, graphical, and web interfaces to view the database.
Strangely I haven't found yet a tool like spacemonger or spacesniffer for Linux. None have that square layout so ncdu it is.
Edit: I am trying something new here. Usually when I have beeninging complain or ask for help regarding a computer problem for a long time the solution appears in the minute in the comments or in a Google search. Fingers crossed.
https://apps.gnome.org/app/org.gnome.baobab/