Civilization VI's mod system is great!
There is one downside: you can't add a new language via mod. You can add a language via user Text directory, but that isn't really convenient if you otherwise can make everything work via a mod. And there is no Workshop or mod support to access user's Text directory.
|Rise & Fall||Yes|
|Adds a new language||No|
Civilization V's mod system is awful.
Doing stuff via Text directory works though: you can add a new language. However there is no longer
an option to select a language in the game options and the only way to change it is to edit
config.ini - not all that convenient.