This is a symptom of flat design. When you remove texture, shadow, and borders, you have to rely more on margins to group and distinguish items.
I could see this being a "pick two" scenario:
1) Low visual noise
2) High visual legibility
3) High density
The industry used to pick 2 and 3, now they tend towards 1 and 2, but it may genuinely not be possible to have all three
It might be a touch ugly, but as an example, if the main interface were black and the URL bar were white, you could nix all the texture/shadow/borders/margins you want and still be fine.