Human readable project files
One good use of this is when you get a corrupted project file. This is extremely rare but can happen because of a power cut or some dodgy plugins.
You can still go back to your automated backup version, but if you want to manually view and edit the project file, this is possible.
This saved me one day when an early version of a plugin was causing issues at project load. I was able to set offline all instances of the plugin.