The court case was about the Espionage Act of 1917, and was extremely unconstitutional. It was about speaking about against the draft.
Holmes justified his ruling with the fire statement at the end of the case, but it has nothing to do with constitutional law, it was an emotional statement.
The court case itself was unconstitutional, and that statement everyone repeats has no legal binding whatsoever as it had no bearing on anything. I doubt you agree with the outcome of that case (socialists being imprisoned for speaking out against the draft) so why would you use an emotional statement used to justify it?
Private companies are not free to do whatever they want, there are regulations. When companies get too large they should be regulated. You can argue these companies have possibly outgrown their Section 230 immunities as they are no longer acting as a neutral platform. They are editorializing their content, acting as a publisher. The social media giants are entrenched with government and businesses solely using them for support and communications, you cannot simply move off.
I guess you are very pro corporate and you feel like corporations should be able to do whatever they want whenever they want.
It being legally okay, does not make it morally okay and laws can change to meet the morals. Maybe we should apply the 1A to these platforms.