To advertisers. Advertisers obviously find this data valuable because it allows them to advertise which is difficult to do on a site without advertisements.
And to me, it should be said, and that Google and other middleman leeches on society shove their foot in the door with the flimsiest of pretenses, then peek into my medicine cabinet, take notes on my bookshelves, and look over my shoulder at my purchases, viewing habits, and rabbit hole explorations for their own profit while resisting entreaties to just fucking cut it out at all turns, is deplorable.
Those who work for them contribute to this miasma. Those who fund them are the root of much of the ill in our society.
They are a cancerous rot.