(An Android ad blocker would probably work best, but getting one running on my ancient phone was more hassle than I wanted.)
I rarely see ads on my android (I do use ad blocker for Web browsing).
I have an incentive to block that as hard as humanly, or computationally, possible.
I see parallels to the 3rd class rail (or coach-class air) problem. If you improve the conditions of the lowest service class, nobody upgrades to higher levels of service. So the lowest class is intentionally bad.
Or substituting in first names of friends in paid content ("<person with same name as your friend> give the following reasons to vote x!/buy this").
Not to mention that if advertising works - then it undermines the idea of a free marked where purchases are made by informed independent agents (I think that's a fantasy anyway, but it seems to be a somewhat popular idea).
Is there anything inherently bad about a stalker passively observing and recording your every move, as long as they don't disturb your daily routine or pass the data along?
Even if you find the stalking behavior (cross-site tracking) of ad companies acceptable, there is a significant risk that your data leaks or is stolen. So, I should be able to decide who I trust with saving intimate data and who I don't.