Hi. I’m not an American, but when you say “these are our first amendment rights”, I assume you refer to the words:
“Congress shall make no law … abridging the freedom of speech”.
That’s Congress. Not PayPal. Congress. The First Amendment does NOT say “Nobody shall do anything that abridges freedom of speech”.
If you’re on my lawn, shouting shit, I can make you shut up and that’s perfectly legal and right and how the world works.
Imagine what hell an alternative universe would be in which anyone could say anything without fear of consequence.