The major other reason is that it is free, and most people are money-constrained.

Personalized advertising is a progressive tax. Because the rich spend more and the poor spend less, Meta et al makes more money from the rich than it makes from the poor, while offering the same service to everybody else. As a result, we get the educated rich upper-middle class complaining about advertising, while everybody else is happy about not having to pay their long-distance charges any more.