What is "Freedom of Speech" in the modern era?

So first of all we have to get the information. What exactly does the First Amendment say about freedom of speech?

"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."

This is a great example of how the founding fathers could never have imagined where the Press and Free Speech would lead us. But it has, so now we have to ask a question. When we post on social media, such as Twitter, Facebook and other social media platforms is our speech protected?

Or do we sign our rights away with the terms of service of each of those social networks which are private companies? The First Amendment does specifically say "congress" shall make no law. So what do we do about these private companies who are infringing on our speech?

I say we should not have to give up our right to free speech to use the services, and that anything we should be allowed to say in a public space such as a street corner, we should be allowed to say on social Networks. Without fear of being banned, shadowbanned, having our channels taken down on YouTube, etc.

So do we need to update our laws to update the times? Or does the government simply need to make social networks a public utility which would guarantee Us free speech protections while allowing them to continue making their profits?

What are your thoughts? I would love to know them and discuss them below.