This is probably not-entirely-useful, because it's just a complaint and not a fix, so apologies for that, but if I may...
My dream solution for some of those issues with integration of Wikipedia and Wikidata is letting people edit Wikidata without leaving Wikipedia (or Wikivoyage, or whatever).
Adding interlanguage links to an article that doesn't have any links currently already works well for over a year: The editor sees a dialog box that does everything needed without leaving Wikipedia, in the user's own language and without ever leaving the page. This is awesome, and it should work the same way for adding links to a page that already has some.
And it should be like that for editing statements, too. In the same dream setup that I am thinking of, statements are edited right in the infobox, and the values are stored in
wikidata.org. Clever local gadgets and templates on the Russian Wikipedia are frequently brought up when discussing this topic. I wish I could see something like this in all languages as part of the Wikibase/Wikidata product and not as a local hack, as great as it is.