Also keeps your base system clean if you uninstall (big reason why docker is so popular on servers). Can create custom environments for a project then just delete everything when you’re done.
Also very useful on immutable distros like Fedora Silverblue (all my command line programs and some gui programs are in a distrobox container, exported to the host so they are just there like normal).
The Distrobox assemble command allows you to install programs from a file and automatically export (unfortunately there’s some bugs I hope are fixed soon). So things can be declarative like nixos.