Social media platforms are private companies and have the right to enforce rules. The banning of Donald Trump?s social media accounts is not a violation of the 1st amendment because the amendment only applies to government platforms. Learn more:

Compliance with social media Terms of Service are required of all users for account creation and usage of the private media platform. Pursuant to Twitter ToS, repeat violations of ToS will result in account suspension.

"Silicon Valley Cartel" is a nonexistent entity (seems to be attempting to evoke potential negative associations of the term cartel). Private platforms banning users, who have agreed to their terms of service, are not "attacking" free speech, just enforcing agreed-upon rules.