Except when a bug pops up somewhere. Ownership/Responsibility changes in sub-Planck-second time when assigning blame.

Noone asked

The CLI is scriptable/automatable and unambiguous when sharing instructions with coworkers. Both of these things make it very useful to know the commands. I do agree that it helps in some situations to visualize what is going on with a GUI/TUI though (neogit for nvim or magit for emacs are great if anyone is wondering), it can make things clearer at a glance.

And how does that work? How do you unmount the root directory of a live system and invoke a script?

Nextcloud is a FOSS fork of OwnCloud. Both projects are great in their own way, hugely successful and serve a lot of people very well. They just moved in different directions.

This is just one example of many. Ability to fork is super important to ensure that projects stay open source, like in this example.