Of course they should not. Or should they? We live in a free society and you are voluntarily participating. Or not. It's your choice. And that's wonderful.
People do not realise, how simple it is to stop. As with cigarettes the real trick is to just not do it anymore. You need some willpower and some plan to cope with the temporary withdrawal effects.
Single datapoint: I briefly used FB for a few weeks about ten years ago, but never saw its value. Today, thanks to dusty email and many other (more open) sites, I have a growing number of friends around the globe and locally.
There are places (like Central Asia), which are already operating in a Free Basics mode in that basically anything beyond facebook is an extreme hurdle to use. But anyone in the western world with lots of choices can stop feeding FB today, if they cared.