I disabled the use of custom fonts and have to say that the material style of Google makes websites unreadable. Just like this framework does.

This is because the span inside an icon has a huge font size. And they use ligatures for characters (so I'm seeing the huge ligatures).

Why would someone choose ligatures over CSS classes?

Edit: I was thinking about problems with screen readers and so on. A CSS class is just styling, but what Google uses is content.