Ad blockers are everywhere nowadays. You can install them on pretty much any device that exists. No company can survive off of traditional advertising. If they can make more money off of targeted ads, why shouldn't they? Just like Apple makes a penny every where they can, including not including certain parts with new phones to save a few pennies. As long as Facebook is operating with the law, and people have a choice whether or not to use their service they aren't doing anything wrong.I agree with the point that not everyone the world over could afford to use a subscription variation of a service such as Facebook. Of that there is absolutely no doubt and no argument. However, it is possible for a service to be both advertising funded and privacy focused.
There seems to be this bizarre notion that one must collect personal and/or private information in order to profit from it. It is an utter fallacy. With a user base as large as Facebook, companies will pay to have their adverts shown no matter what. They do not have to target them specifically to an individual user, because those same users will see the advert regardless if it is shown across the board.
Yes, tracked advertising is without doubt more efficient and almost certainly more profitable for the platform hosting the adverts. But absolutely necessary for the survival of the hosting platform? No, that I could never believe, not when there has been so much evidence to the contrary - Specifically, every business that ever existed with advertising funded operations, before tracked advertising was ever a thing.