The issue with social media isn't the free flow of information but the
amplification of certain information — the information that tends to make you angry. The amplification is the cause of echo chambers, spreading of misinformation and disinformation, etc. It makes possible what in essence is a distributed denial of service attack on the human brain.
Sure, chain emails existed before, but they had a pretty low ceiling of how many it would reach. It didn't scale well.
In other words, you should regulate the amplification mechanism ("algorithm"), not what information is allowed to be said. I think forcing platforms to go back to subscribe+reverse chronological feeds would be a pretty good start.