I actually intended to make this post a year or two ago, but then kept putting it off. Now I stopped doing that, so here you are.
What is this about? I don't mean to criticize how bloated the browsers have became, even if it's true. I don't mean to write about how Firefox always shuffles UI elements around or how Chrome spies on its users. Just the very simple, most basic thing. Fonts and font rendering.
Make sure to set your browser page zoom to 100% to avoid browser scaling image distortions.
Here's a tiny piece of html for this test.