Are you sure you are not missing the point? Whether curated or not, the expectation of users certainly is not that it's curated according to facebook's interest

Are you sure you are not missing the point? Whether curated or not, the expectation of users certainly is not that it's curated according to facebook's interest of the day, but according to their own interests (that is, to reduce noise, not to influence them), and whether perfect or not, people certainly do expect and counteract lying in ads. Also, just because ads are generally perceived with some scepticism, doesn't mean that certain kinds of ads aren't unethical as well. In particular, ads that exploit methods of bypassing rational thought might indeed be unethical, and certainly are not the same as just general self-interested advertisement. And despite what you claim, manipulation is actually not a defining property of ads - if you have a product to sell that is actually a rational thing to buy, advertisement can use perfectly rational thinking in order to pursuade you to buy it. Just because much of end-consumer directed advertisement nowadays is trying to sell bullshit, doesn't mean that advertisement can only be used to sell bullshit.