- PBR rendering AKA 'realistic' lighting. Video games used to entirely fake the lighting, just using some artistic approximation of what looks decent. And when it was too dark, they just cranked up the ambient light.
- Greebling. Artists are directly at odds with the designers, artists want their work to be interesting and stand out… which draws attention away from important details that the designer wants to be interesting and stand out.
Look at all the various normal-mapped surfaces that have crevices/peaks just to look artistically interesting. These are intended to draw your eye, because the artist wants you to look at them. But they don't actually serve a gameplay purpose. The scene is visually busy.
(Perhaps a bit unfair as this is the enhanced edition, but old games at high resolution tend to be extremely 'clean')
With regards to #1, I actually think the issue here is most games aren't using enough light bounces when baking the lighting and/or rely entirely on real-time GI. Those lights should be contributing significantly more to the overall brightness levels rather than just lighting up their immediate area. Perhaps this is due to a lack of training with the tools, or bad documentation.
I don't agree with the notion that the UI is tied to this, not in most cases anyways. The bottom one actually has a busier UI.
Of course, early true 3D games tend to be even better at visual clarity.
I find these early 3D games combined with modern high resolution textures to be an ideal for me. Note the ambient lighting ensuring a minimum level of brightness to prevent anything from being overly dark.
(Grabbed these from the GOG page for System Shock 2 Enhanced, feel free to post some more early 3D stuff highlighting visual clarity)