Imo, I do think social media needs to be reeled in by policy. But I can see why it makes people uncomfortable and why there is a difference with the saw.
Arguably, the presence of social media homogenizes the speech we're allowed to have.
The historical existence is simply irrelevant. Just like existence of pre-TV/newspaper speech is not a relevant factor in determining whether banning all TV/newspapers in 1950 restricts free speech
Naomi Klein went into this in No Logo with shopping malls replacing public spaces where you also don’t have a right to free speech and can be evicted arbitrarily at the owners discretion.
You’ll find virtually all of social media platforms have moderation, usage policies and user banning practices that go well beyond allowing the fully legally protected free speech you are afforded in a public space (in many countries).
Edit: removed unnecessarily inflammatory phrasing.
a lot of ppl got reeled into the narrative that social media can democratize (free) publication of conversations and ideas, thou it is dominated by monetary incentives that mandate propaganda/advertising and in turn moderation and censorship.
The proper analogy would be banning books with certain content, which we already do. You can't distribute a book calling for a specific person to be killed or doxxing them. Doing this on social media in Ethiopia is encouraged, as it drives engagement and has lead to actual deaths of people I know. They have a policy not to moderate this content despite having the resources. Just like they have a policy to make the apps as addictive as possible.
More importantly, Facebook is not a "printed book", it is the printing press. It owns the internet. It's not remotely comparable. And that's why it is a threat to free speech
It would be as if printing presses were so complicated and expensive that the barrier to entry was so high as to price out everyone but a few select publishers. I wouldn't try to over-extend that metaphor though.
> if the addition of seatbelts say doubled the price of car
Seatbelts are brought up so often precisely because they are an intervention with a huge benefit-to-cost ratio. Seatbelt laws were made long after the fact - seat belts for cars started to appear in the 1950s, with the common three-point variant in 1955; the first seatbelt law appeared in 1970 (in Australia). The US started introducing seatbelt laws for cars in the 1980s (though as far as I know, some organizations/insurers required them earlier for employees driving for business).