Third party cookies aren't the only thing that's tracking you. You can be tracked by first party cookies, local storage, your IP address, browser fingerprinting and other techniques. GDPR requires websites to get your explicit consent for any kind of tracking.
A lot of users are already blocking third party cookies and that's the default in Safari and Chrome nowadays - but ad companies have moved on.
I don't get it. A public site is like a public store. Do you have the expectation of privacy in a store? No not really. And be sure stores do track you.
> Do you have the expectation of privacy in a store?
Yes, absolutely. I don't have an expectation of having as much privacy as I do when in a private residence with the blinds closed, but I do have an expectation of some forms of privacy.
* The store will not perform a full strip-search of my person upon entering.
* The store will not place a GPS tracker on me as I leave, to determine where I live.
* The store will not have a team of employees with clipboards follow me at all times, making notes of my location within the store.
* The store will not keep a record of my eye movements, correlated against which products are being glanced at.
The problem is that, as technology has advanced, some forms of privacy that used to be protected by impracticality of implementation no longer have that protection. For example:
* The store will keep video record of my visit for a few weeks at the most.
* The store will not analyze video records outside of suspected shoplifting.
* Record of previous purchases is limited to the cashier's memory.
Privacy is not a binary yes/no decision. As technology improves, forms of privacy that were previously protected by limitations of implementation must be protected through other means.
I have the expectation that when I enter a store that the store keeper doesn't sic his minions to sniff after me while I browse other stores and for good measure maybe peeks into my bedroom.
Physical stores don't do that and therefore your analogy breaks down.
They do put electronic advertising screens in front that collect "anonymous" mac addresses. They also put trackers inside the shopping carts to follow you inside the store. The client-card you use during checkout records your name, address and spending habits.
They don't need to sic a minion to sniff after you. The implication of buying condoms and then visiting the hotel only requires to correlate three tables.
In this case the agent would be well a literal agent. Nobody is requiring your agent to walk around and advertise who you are, to accept every cookie or display an advert on its shirt while walking around the store for you
For your analogy to be more accurate, any store I walk into would have the ability to look at my behavior in every store, essentially in perpetuity, and share/sell that information. Feels like something you should at least have to opt into.
Visa only tracks purchases. Surveillance ad tech can track literally everything your browser is doing. Did you go to Reddit today, what subreddit, what posts, who did you reply to, etc. Or, did you visit a porn site today, or a dissident political site, or a marketplace for abortion drugs that are illegal in your state. There is no meatspace analog; the comparison is absurd.
Visa tracks did you purchase porn, did you buy something from Infowars.com, did you buy abortion pills, etc. That's only one source for data that advertisers use in the physical world. You think that's a big difference?
A lot of users are already blocking third party cookies and that's the default in Safari and Chrome nowadays - but ad companies have moved on.