If you want to control the platform, create your own. You'll need the hardware and the software, and it could get expensive. But if you want to spread hate speech or libel, suck up the cost.
If you want to be on someone else's platform you accept the restrictions of using that platform. Hate speech is on the list of almost every major platform (except Twitter).
De platforming people who spew vile (but legal) speech isn't good for society
On the contrary, I think it's very good for the same reason I would want to drain an abscess or excise a tumor. The vile speech that you mention isn't harmless, and the people targeted by vile speech are part of society. What benefit is achieved that exceeds the costs imposed upon them?
The Supreme Court seemed to have very different take (Packingham v. North Carolina):
"Social media allows users to gain access to information and communicate with one another on any subject that might come to mind. With one broad stroke, North Carolina bars access to what for many are the principal sources for knowing current events, checking ads for employment, speaking and listening in the modern public square, and otherwise exploring the vast realms of human thought and knowledge. Foreclosing access to social media altogether thus prevents users from engaging in the legitimate exercise of First Amendment rights."
North Carolina was also banning convicts' access to multiple websites, so it was more of an internet ban.
(It helps to read the entire case.)