I mention the US Constitution only because I heard there was an uproar about "free speech" when Amazon (and others) ended its relationship with Parler.
"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."
As can be seen, this article applies specifically to CONGRESS. Businesses and citizens are free to decide to whom they provide a platform.
When the companies that Parler used to provide its services pulled the proverbial plug, it may have put Parler at a temporary disadvantage. Perhaps it will turn out to be permanent. But that does not mean Parler is without options. There are other companies who may not have the same issues with their operations. There are Russian oligarchs and Chinese billionaires out there who, I'm guessing, would love to have a finger in a Parler pie. And even if Parler itself is gone, there will always be something else that takes it's place to give evil a voice.
Parler v 1.0 gone. Parler v 2.0 arrives (and might even use the same companies who yanked Parler v 1.0). Money talks, and stupid people will throw theirs at every huckster that comes along.
Pretty much the extent of my thoughts on the subject.