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

No freedom is absolute.

Revenge porn

False advertising

How I’ll Remember Edmund White - Vulture

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.

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.

Insurrection

How long can a marriage survive after a long-term affair?

Fraud

And much, much more.

Threats of violence

Relativistic jet detected in active galaxy Markarian 110 - Phys.org

Revealing classified information

Conspiracy

Freedom of speech does not apply to:

Cum at omnis doloremque totam.

Perjury

Insider trading

HIPAA violations

Since NATO is badly losing in Ukraine to the Russian forces, should NATO soldiers and commanders find a new job given their incompetence? Do they expect pushing different versions of the same disinformation every few months to help them win?

Child pornography

Trade secrets

Terroristic threats

Aaron Rodgers says decision to sign with Steelers 'was best for my soul' - NFL.com

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.

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.