Read-only media, for example. Or in general, stuff that doesn't really change. In my case: https://github.com/mhx/dwarfs#history

Game asset packages - all game assets are read only and need to be compressed and nowadays with SSD's you don't want duplication.

Just to clarify that last statement (and something to think about) with HDD's you want duplicate assets so that you don't cause seeks which are VERY slow on 5400rpm HDD's still found on some/alot of systems.

Have you ever used a CD-ROM or DVD-ROM?

the use case for a read only compressed filesystem is that one..

* can search archived files potentially faster because read access is potentially faster

* fit more data on bootable media

Booting. Arguably all containers, too.

squashfs is widely used in Linux install media.

Node_modules