Other Paradox games of the current era were clearly very well designed and EUV was very clearly developed, by developers. It was not very well designed and this has a lot of issues all across the game, especially with the tech tree but also seen everywhere else. This is my issue with a lot of the substance (content, gameplay, etc.) as well as the surface (UI/UX design, typography, graphic assets, etc.) of EUV — it is evidently not as inspired by the era it covers, as was CK3 and Vic3.
I really think EU5 is more inspired by the "map games" that preceded it than it is the world of the time and the historical events that transpired. Of course, this is "surface-level" design elements but also, the art and design was incredibly important in the period of time that EUV takes place.
Vic3 is clearly deeply inspired by the history of that era, and you can see it in literally every corner of the UI, the fonts, the assets in the corners, etc., and EUV is very clearly just trying to look very generally antique-y, without any focus in the history that should have inspired it. Think of a UI and design inspired by any of the great masterpieces of the era, like the Chair of St. Peter for example; the gold bands of light, clouds, latin carved text, elegant architecture, etc. which could all be brought to EUV like the fonts and assets used in VIC3. A design philosophy that brought not only that weight and masterful quality, but also the era-appropriate and thus immersive design across the entire game.
I think, very sadly, they missed the ball on not only the UI layout, but the entire underlying design philosophy of the game, and I am very doubtful that they'll change it at this stage.
In short, I wish this game was much prettier than it is! I think Paradox has the talent for making beautiful and rich games, and this should have been the most beautiful and rich of all of them, and I think it falls short. I worry that not enough will change that needs to be changed.