Section 230 itself already does not apply to federal criminal investigations, including investigations of child sexual abuse. A social media company should not bear legal responsiblity to detect crimes before law enforcement does.
Counterpoint - Businesses are generally liable in the physical world for harms caused on their premises by a foreseeable hazard. Whether as simple as a pothole in a parking lot that causes injury or an unstable shelf that collapses, …
The major social media sites know absolutely that their products expose customers and users to predictable harm and cause real damages. They should bear an analogous liability burden as a business operating a physical location.
In the case of Meta, X, et. al., the conversation is an integral part of the product. It isn't incidental "around their premises".
You're also wrong though - a corporation is absolutely liable for threats and various types of verbal harassment that occurs within their walls. Thus the endless liability-offsetting mandatory training videos... Duty of care is well established.
> ...a corporation is absolutely liable for threats and various types of verbal harassment that occurs within their walls.
From its employees or contractors, possibly. From customers or visitors? Absolutely not.
> ...the conversation is an integral part of the product.
For telephone, text messaging, and mail [0] the conversation is an integral part of the product. And yet, somehow they don't have this "liability burden" you're asserting is borne by everyone who provides a service or a space where people could plausibly speak with each other.