In principle, I agree with your point; in practice, I think the claims made my these surveillance/advertising companies are likely as overstated as Musk's last decade of self-driving that still can't take a vehicle all the way across the USA without supervision in response to a phone summons.

The evidence I have that causes me to believe them to be overstated, is how even Facebook has frequently shown me ads that inherently make errors about my gender, nationality, the country I live in, and the languages I speak, and those are things they should've been able to figure out with my name, GeoIP, and the occasional message I write.