The two root causes of these sort of windows disappearing is what you've said (DPI) and just a change in tastes. People now view those styles as kind of garish

The two root causes of these sort of windows disappearing is what you've said (DPI) and just a change in tastes. People now view those styles as kind of garish. Between that and the difficulty of making it work and look good at a variety of DPIs, it just wasn't going to stick around. I admit, I like things to have some more color and texture. Simple black and white boxes are a bit soul crushing. But I see why they disappeared.