Arguing that Medium beats Cracked because of their fonts is a bit disingenuous. Open Cracked in Chrome, delete a couple of the most glaring nodes in the element inspector, zoom a notch or two to get a hipper x-height, and you'll see that the main difference is in their revenue models. Comic Sans is not even an option in my Blogger draft window. Did you have to make extra effort for that? How about some nice Georgia or Trebuchet?
The most important thing with choosing a font is to make sure the letters are easily decipherable from one another so your readers don’t have to spend precious mental energy identifying letters.
When was the last time you spent precious mental energy trying to distinguish the numeral 1 from the letter l? Probably when you were trying to Google a product code or serial number. This is not "the most important thing." The important thing is to use a font that is readable and looks nice. The Medium fad is a nice correction to the tendency of cramming as much as possible into a browser window before the fickle user has a chance to click away, but I would prefer to read more than 20 seconds before having to scroll.