If freedom of speech is absolute, how come it's not applied for private spaces and for the Internet?

That’s what it is. You have no right to use other people’s stuff. If people let you use their stuff, they can tell you how you can use it, and they can tell you to stop using it any time they want.

Fraud

Revenge porn

Why are there so many single moms in America?

Conspiracy

Trade secrets

Child pornography

Why is it so hard to date nowadays?

False advertising

You have freedom to travel. If I loan you my car, I can tell you not to take it out of town, because it’s mine, you have no right to use it, and if I give you permission to use it I can tell you what you can and can’t do with it.

HIPAA violations

Is Matt Gaetz qualified to be Attorney General of the United States?

Freedom of speech does not apply to:

Insurrection

And much, much more.

Why are American university students fine with sharing a room?

Insider trading

Revealing classified information

Threats of violence

Record-breaking cosmic structure discovered in colossal galaxy cluster - Phys.org

Terroristic threats

If you’re wondering why free speech doesn’t apply to the internet, it’s because you have no right to use other people’s stuff for free.

No freedom is absolute.

Why is America so fucked up?

Perjury

You have freedom of speech. If I loan you my computer, I can tell you not to use it for certain things, because it’s mine, you have no right to use it, and if I give you permission to use it I can tell you what you can and can’t do with it.