It's probably about the font just being well designed, having consistent kerning ans whatnot. Same as with design guidelines. Every couple years something new

It's probably about the font just being well designed, having consistent kerning ans whatnot. Same as with design guidelines. Every couple years something new comes along and is better than anything before. We had an intern a few years ago who was still working on his masters and also made some money on the side with "web stuff". He wouldn't stop talking about material design, how it is the best ever and how every margin and padding is scientifically proven to be perfect to the pixel, the blue they picked is perfection, how rounded corners and 3D effects on buttons are fatiguing to the eye, and so on and so on. I guess it was the first time this fellow consciously witnessed the release of a web design framework. It was near impossible to convince him that using bootstrap is just as good, and while certain rules for ratios between paddings, margins and font sizes exist it's much more important your theme is consistent, and that you apply it consistently.