Let's take a look at Cisco Umbrella 1 Million list http://s3-us-west-1.amazonaws.com/umbrella-static/index.html
As I write this fonts.google.com is the 44th most requested DNS lookup in the world. DNS request- not domain. Because every where you go you run into Google Fonts.
That's more popular than msn.com, icloud,com, amazon.com, twitter.com, instagram, ... basically every other thing in the world except the 43 above it.
I get that you say disabling Google fonts w/ an ad blocker or in your browser would solve it but it doesn't
my browser still downloads a css file from them
<link href="https://fonts.googleapis.com/css?family=Lato:300,400,400i,700|Roboto+Mono:400,700" rel="stylesheet">