The default way that Kirby handles multi-language websites, is that there is only one page tree structure. That is, the default language is the master that defines the page tree structure. This is a solution that works well for a lot of different types of websites, but not all.
I would like to see the option for an independent page tree structure for every language defined. For example I may want to have a specific page only available in the german version of the site. And another page only available in the swedish version of the site.
Also, in the panel, I would like to be able to only show pages from a specific language and hide the rest.
See also this thread regarding this: