That's not how freedom of speech works at all. These are not publicly funded platforms. They are businesses and as such need to censor speech in order to maintain relationships with businesses. Twitter is a great example. They start to loosen up on the hate speech and advertisers flee while simultaneously clamping down on anti government speech. I do not support free speech absolutism for private businesses because of this. It just doesn't make good business sense.
Multiple people saying the same thing so I guess I'll reply to yours.
However these are communications platforms. So is it clear that if AT&T wanted it could say I cannot talk about my silly hats only club, they could intervene to block my communications?
Or if my landlord felt I shouldn't have a specific sign (not signs in general), or even to just say words they dont agree with, they could bar that from their property?
Or if I wanted to wear a democrat colored pair of shorts to a (business owned) pool they could bar that dress code?
These are all business contexts in which I'm using the business owners property as a customer/consumer and hypothetically being barred from an action. I dont see how it's so different for communications platforms like Reddit/FB/YT
Or the facts of every circumstance matters a lot more in how the law is applied than you are willing to give it credit for.
A telecoms company like AT&T is subject to common carrier provisions and regulation by the FCC under the Communications Act of 1934.
If a landlord wanted to prevent you from putting up signs on the property, they probably can put that in the lease agreement but their free speech interests and property interests while still dominant are compromised to an extent as well by having rented the property out to you, but not to the extent that your free speech and property interests (like your personal property) are entirely compromised either. Their ability to evict is dependent on jurisdiction, but such a case would likely turn a lot on the facts depending on the jurisdiction.
Dress codes however can be arbitrary. You can be excluded from a club because the owner doesn’t like your shoes, and yes, that’s legal. Their property interest in this case entirely trumps your free speech interest. Having strong property rights is in part why we are a free nation, but sometimes when there are clashing interests, someone’s interests are going to win out and 9/10 it will be in favor of the property owner’s interest.