I believe you misrepresented that algorithm. While it is true that Shamir's Secret Sharing is unbreakable if you split the actual clear text among participants, it is not used that way. The actual use is to use SSS to encrypt and distribute the key used to encrypt the clear text.

I think you are describing a larger encryption scheme that uses SSS as a component. I am talking about SSS itself, which is unbreakable, from an information theoretic standpoint. You can use SSS to split the clear text among all participants, even if most people don't use it that way to construct larger systems.