Facebook are an advertising platform. They only offer a paid tier because they now legally have to. They don’t really want you to take the paid tier, they want you to explicitly opt in to the ad-supported ‘free’ one. - because by specifically agreeing to "I want the free Facebook with ads’ option it means you’re actively choosing to be served ads, which is what all the recent lawsuits have been about - users giving explicit consent to be targeted for advertising.