Google is an advertising network, they don't need to sell the IP to make money.
It's on the original website to prove that they only use your data for what you asked them to, if you want to do anything else, you need to request informed consent.
Using hosted Google fonts is not needed to run the website (as you can also easily embed them without having the user touch Google). And Google will not say they won't do anything with that data, as they would be lying since that's the whole reason google fonts and other free webdev resources by Google exists: to gather as much data about the user it can.
It's on the original website to prove that they only use your data for what you asked them to, if you want to do anything else, you need to request informed consent. Using hosted Google fonts is not needed to run the website (as you can also easily embed them without having the user touch Google). And Google will not say they won't do anything with that data, as they would be lying since that's the whole reason google fonts and other free webdev resources by Google exists: to gather as much data about the user it can.