>>12123006
>>12123012
Both of these things are true but another factor we can't ignore is that the UI in modern games have to be much more scalable than they were in the past. A lot of the games in that pic were made with a max resolution in mind, like 640x480. When you know the exact dimensions and resolution that your players will realistically be viewing the UI at, it gives you a lot more freedom to go nuts with nicely detailed pre-rendered images. It didn't matter if those same images might look blurry at 2-3x times the resolution, because very few people were going to be seeing your game at a res higher than what you tailor made it for anyway.
Now every game has to be legible at 720p, 1080p, 1440p and 4K. Forget nice little bespoke images and fonts, just use some vector shit that will scale easily to fit the user's screen. There are plenty of modern games with nice UI's, like Persona 5, but they're the exception, not the rule.
Comparing Oblivion's UI to Skyrim's is basically a case study in where it all went wrong. There was absolutely no fucking reason for that nordic viking fantasy game to have the UI of an Apple product. But Bethesda wanted something sleek, "timeless", and again, scalable so they wouldn't have to re-do the interface every time they ported it.