And that's a huge problem. The notion of a "pixel-perfect design" doesn't belong on the web. In the case you mention, you're sacrificing accessibility for control over what your users see. You're kind of telling your users that you know what they want better then they do. That they should be able to read the small type you put in front of them, even if their eyes are bad.

CognitiveLens is right. Proportions matter.

(Note: when I say "you", I refer to the "one [who] wants a pixel-perfect layout" which may or not actually be you.)

The problem is that pixel-perfect layouts are no longer pixel perfect when the page zooms and the text doesn't, or vice versa. Full page zoom keeps everything in proportion.