Government regulation is no substitute for competition. The ability for consumers to walk away to a suitable alternative maintains a continual accountability that a single agency is unlikely to deliver.
Take myself for example. I only ever get angry when I browse my facebook feed and for some reason I've actually taken steps to ensure I get angry when I browse my own feed (chalk it up to silicon magic). I would like to leave facebook, but if I do I'd lose messenger which is the easiest and most consistent way for me to keep in contact with dozens of people (who mostly don't make me angry).
If facebook protocols were open source, then by now I would likely have dozens of different options to take my friend's list to a messenger only app that does not include a feed for me to angrily browse.
Lowering the cost to leave is a benefit to everyone since it reduces the reach of that anger inducing feed.