Won't disagree with you
I won't disagree that amending the Constitution can be, and has been done. It's a difficult process on purpose on purpose and I think removal of any of the Bill Of Rights would be difficult, if not result in a second civil war.
No, they simply use Executive Orders and legislative and administrative law to limit our freedoms.
Ask yourself the next time there is a political convention, why in the world there is a Free Speech Zone.