The First Amendment and freedom of speech are NOT synonymous. The First Amendment is only one legal protection of free speech in one context. It is true that banning Trump from Twitter does not violate the First Amendment, but it is a violation of freedom of speech. We live in a world there the speech that used to occur as literal speech in public places, protected by the First Amendment, now occurs largely online on Twitter and Facebook and such. They fill the role of providing a medium for speech which used to be filled by the government, and we need to hold them to the same standards. You have also misconstrued the point of section 230. Section 230 says that platforms cannot be held laible for what users post, it is there to allow platforms to respect free speech, not to give them discretion not to.It is true that smaller-scale entities like SSC or LW regulating content is not necessarily bad. There are thousands of blogs on the scale of LW or SSC, there is only one Twitter and one Facebook, and really nothing else on that scale. In order to have a healthy ecosystem for exchanging ideas, the larger platforms need to respect freedom of speech on their platforms, in the same way that the First Amendment requires of the government. How big does a platform need to be before it needs to respect freedom of speech? I don’t know, there may be a gray area, but Twitter is definitely not in the gray area.