u/Merowich_I

TlDR: Different skins to the UI make the game feel make a significant impact on how I play the game.

Every time I’m playing a nation that got a DLC I would say about a good 25% of the nice feeling for the nation are the graphical elements, like map skin etc.
For example with the Balkan map that has a lot of painting in the oceans, gently telling the player that this part of the game is not as relevant for me is a gameplay plus.
In my current Japan run I get a much better feel for the nation with all the assets.
I would even go so far that they should make dedicated UI skins for as many nations as possible; maybe even doing a dlc that is only assets for smaller nations that probably won’t get a full content dlc as a bundle.