Most of their stuff doesn't directly serve ads, I don't remember ever seeing one on Google Assistant or in Gmail. They seem to mostly just exist to do tracking

Most of their stuff doesn't directly serve ads, I don't remember ever seeing one on Google Assistant or in Gmail. They seem to mostly just exist to do tracking to enhance the stuff that does do ads, or to add value to some other thing that shows them, but they're not directly ad supported, they're tracking supported or pure promotions.