Many business benefit greatly from some amount of advertisement and it's a practical way to monetise people's attention. What is immoral is the cohort of brilliant minds who've made the optimisation of advertisement the quest of the century.
But as it stands, even if you're willing to forgo using such sites, you have to load trackers to know that the site uses them. So an adblocker/anti-tracker is a necessary protection.
The head of the first French TV channel himself bragged that "his job was to sell available brain time".
On the the other hand if you're complaining about the shady manipulations going on behind the scenes to fuel the data driven marketing and advertising schemes then sure you have a point.
On the other hand, you don't consent to seeing a billboard whilst on public roads, so I don't think I'd object to people "defending themselves" (whatever that looks like) from billboards.