A nice overview of the many variations body copy has seen since the Web exists.
I agree with the conclusion:
I’m […] sad that we’re somehow chasing after device makers, operating system and browser developers, and trying to tweak font sizes every other year to adapt to what is out there in the market. The very concept of raising font size a bit depending on the screen width should raise eyebrows. Isn’t it the device’s job to make sure that font-size: 100% is readable?
It should indeed be the device's job to make sure
font-size: 100% is readable for most users, but don't forget it's the developer's job to make sure people can change their preferred root font size if this default size is not the best for them.