I disagree. Facebook makes their money from advertisers. The advertisers go where people are, but they are also careful about paying. For example if their product is only applicable to one gender, but the ads would go to everyone then they'd want to pay half as much. Sites that do not have demographic information about their users consequently can't charge anywhere near as much as Facebook which gets advertisers to pay more for the demographics they want.

Even if everything in your FB profile is a lie, your friends then provide the demographic information about you. eg you are going to similar to them.

And because you are on Facebook, you are now available to the advertisers.

You probably still view ads on the Facebook platform, though, right? You may not contribute much to Facebook's analytics platform, but you're still making them money when they display ads.

Still, you get tracked on your interests online. Those get cross-checked with those of your friends, their friends, your age-group, the area you live in, your other hobbies, etc. providing useful information.

Being in their web has value for them, even if you consciously try to avoid being of value.

Making users think they got the better of them is part of the business model. The only way to win is not to play.

You still contribute to the network effect and to legitimizing FB as a good way to keep in touch.