As for FB’s attempt to create an irreversible fait accompli, it’s easy enough to address: Instagram gets all the shared infrastructure and its transitive closure, and it’s Facebook’s task to replace it for itself, not the spun-off Instagram.

If we break up Insta and FB (and whatapp or the same for google), what changes? There is more competition maybe. But is that actually a good thing for the average citizen?

More competition means lower prices for ads since that's what is really being bought and sold here. But that does nothing for anyone not buying ads (99.9% of people). In fact, lower prices means more ads which worsens the experience for Web users.

Plus, with a psudo monopoly on ads, FB can and does pursue at least some social responsibility programs (banning certain ads for instance). Maybe they should do more (I think so but you might not?), but if you increase competition they will be forced to do less. So you'll see more fake news and clickbait bs. Again, that doesn't help the average citizen.

As margins fall, everyone will be forced to invest less in the actual platforms. This too seems like a worse deal for most users: sites that don't have as many functions and load slower and go down more and have more ads.

Given all these very foreseeable downsides, why would we want more competition in this market? Competition is NOT a good in and of itself. It's only good or bad based on what it produces. Cheaper flight prices are good! Flights so cheap the airplanes crash are bad. So we have the FAA to mandate standards.

Until we're ready to add something similar to social media, you need to be very careful calling for more competition blindly.

But then you have 2 more problems: Facebook 2.0 will like open shortly after, just as Facebook replaced MySpace. And you have random agencies from the US government deciding which platforms are permitted to operate with no oversight or guidance beyond whatever the next President Trump thinks favours him...