The vast majority of their data comes from browser extensions that track the URLs users visit. The other stuff like ISPs, DSPS, etc are there to make you think

The vast majority of their data comes from browser extensions that track the URLs users visit. The other stuff like ISPs, DSPS, etc are there to make you think they have some sophisticated model with a diverse # of sources (don't fall for it, they don't). If Google ever prevents browser extensions from tracking your every visit, their business is in extreme trouble. Full Stop.