Yes, it's important for children to engage with culture, to read, to explore music but this shouldn't be used as an argument to justify everything that can be grouped in under 'connectedness'. It's interesting you put reading there first because that is actually a solitary activity. Today it's arguably much more important to teach kids how to engage with their own minds and how to spend time alone and build out their own personality and views than hooking them into Instagram feeds. Which is not social in any genuine sense of the word.
With that said, everything should be done in moderation. It's a skill important to know whether your socializing, or spending time alone.
The old school online forums were not designed to create such attention. Posts are made asynchronously. Absolute instead of relative timestamps are used.
There are purpose-designed social media software with UX designed to bring people to consensus rather than dissension. They have been used in highly contentious political debates and bring about policy consensus. But you cannot monetize that.
I'm not saying it's easy, i've had some epic battles with my kids in how they handle/navigate the complex social structures around technology in the palms of their hands - but i certainly don't think taking that away does anything and may be detrimental.
Society is all of us... There isn't a single one of us that didn't stay up all night reading a book, watching a movie, talking on the phone, writing a letter, sending "beeper" texts out, texting on smart beepers, getting on BBSs, connecting to internet, having phones, then text messages and so on and so forth. It's all connectedness and culture we've always had, but now more readily available.
Help your children navigate it, grow in it and thrive in it. Be there to keep it safe.