Wouldn't the browser cache make that a fairly ineffective tracking method? The odd bit of data about some websites you visit doesn't particularly benefit Google

Wouldn't the browser cache make that a fairly ineffective tracking method? The odd bit of data about some websites you visit doesn't particularly benefit Google, not nearly as much as the data you give them when you directly use their services. I'd be sure to keep local backups of every font and library you point to just in case something breaks, though.