And? before the internet those ideas didn't spread anyways or they were spread by a small number of media companies. Pre-internet was not this mythical golden age of an exchange of ideas. On the whole of it these small number of tech companies are actually pretty hands off when compared to how legacy media operates. In fact now fringe/"banned" ideas spread faster.
Then build a town square that is publicly owned, we as society decided to wave our hands of the responsibility of making a publicly owned the internet for the convenience of allowing big tech do it for us. The solution is not force private companies to host speech. It either create a publicly owned town square on the internet or collectively stop valuing/using these platforms so much.
It still is a virtue and a right in the US. Freedom of speech is not about giving every idea and every person and equal platform to spread their ideas. It's not about forcing others to host/spread ideas they disagree with. I think the internet has given people a warped sense about what freedom of speech is. We have no less freedom of speech now than we did before social media/internet.
A common thread I see is a lot is people conflating freedom of speech and having a platform (more specifically an online one). Forcing private entities to host speech they don't want to goes against what I define as freedom of speech. Everyone should be entitled to speak and have their own ideas, no individual or company should be force to spread them.