I’ve been using the command line NCDU for a while. Whilst NCDU is nice and fast and does allow navigating the directory tree, you had to go to a file explorer separately to delete anything.
QDirStat is doing a good job of showing everything NCDU did, and more, such as last modified, refresh just a sub-folder, and allowing various delete and clean options right inside the app.
It also has a Discover menu option to specifically find the largest or oldest files, broken symbolic links, sparse files, and files with multiple hard links.
NCDU will probably still work best for remote terminal work, but QDirStat does look very promising for graphical desktop work.