If Twitter were acting strictly alone, that might be a reasonable point. In the case of Facebook, they possess monopoly power and their ability to censor speech is elevated above most of their peers (save for Google).

Twitter however did not act alone. The tech giants conspired together to mass censor speech they politically disagree with in the 2020 presidential election. It's not a conspiracy theory, it's not secret in any regard, they were openly and directly sharing block lists with eachother and acting against only the political party they consider their adversary (rather than equitably enforcing their terms of service, behavior that has been going on for years now).

Their executives should be in prison for that level of criminal collusion toward election interference given their extreme collective monopoly status. Merely breaking the companies into pieces is not enough.