yes of course people should exercise regularly and eat a balanced diet, but so long as it’s cheap and easy to binge Netflix and eat fast food, hundreds of millions of people will settle into that lifestyle
In some cases you "don't have a choice".
I've heard that Facebook is installed automatically in some smart phones and even set to some extremist site/discussion/forum/whatever as default when the person opens that app in the beginning. If you're not tech-savvy, that may lead to even bigger problems...
And then there's the Chinese government's "game". Act like how they want and you get life-made-easier benefits. Talk trash about the government or do some other actions they don't like and...well...
The people who want to eschew mainstream social media for smaller forums will do that, but most people won’t and the societal issues will remain unchanged.
Some folks don't know about the other tools. Some are unsure about them. Some folks feel there's not enough activity/lack required/needed content in the smaller tools so why bother going there in the first place.