I think this is just a red herring for the main discussion here. Of course that example is also terrible! Just because this discussion is about Instagram doesn’t mean we don’t care about anything else.

Speaking to your point more directly, the massive, massive difference is the primary user of Instagram and typical social media vs the primary user of these other platforms. The primary user of Instagram is shown addictive feeds non-stop. It’s really not possible or enjoyable to use Instagram without interacting with designs deliberately and literally trying to get you addicted to the platform. This isn’t true for something like Wikipedia or Stack Overflow. The primary user is going to come across a few articles now and then or search something. But they are rarely going to be interacting with an algorithm or design trying to get you addicted for hours a day.

Think about it like gambling. The only way to use Instagram or Tiktok or Facebook or anything like that is by pulling the lever on a slot machine, trying to get a dopamine hit.

The inherent design and purpose of social media platforms is to addict people so they spend as much time on the platform as possible, and then show them ads. That’s not true for Wikipedia or stack overflow. Those examples are more about policies that encourage toxic behavior or just crappy people on the internet, not a critique of the inherent platform design.

I agree with the points made here but if addiction or useless products is the problem we will have to disallow Netflix to teenagers and gaming as well. It's not clear to me we as a society are capable of doing that. Not only that, probably the whole pop culture and increased individualism is contributing to increased unhappiness. Facebook is just a symptom of a disease in our culture. Dismantling Facebook will do very little to help kids I think. I actually think the Chinese got it right (banning gaming to teenagers above 3 hours per week or something like that), but we don't operate like that.