A good pixel art is good pixel art lol. It could be done,but modern devs lack the skillz and are too lazy to do it.
I think the problem is that in the older days the UI was designed once (or only had a handful of iterations) and you were expected to read the manual and learn how to play the game in case the UI isn't intuitive enough. That and the UI was usually designed for 480p with individual elements having a fixed size, taking less and less screen space in higher resolutions (or stretching the whole UI to fit the screen). In some cases some of these UIs were designed for a single resolution and thus the art team could go crazy with them (e.g. Amiga games).
Today, the UI can get redesigned dozens of times while being focus tested to death (since no one cares to RTFM anymore), not to mention there might be pressure to make it work and look the same on PC, consoles, and mobile platforms. By the time it's done, no one wants to bother with it, so going for something slick and simple starts looking like the best way to finish this part ASAP and focus on something else.