Ancient Athens had ostracism [1]. It was against a single person and not against ideas but given that the numbers where smaller and heads carry ideas, it was more or less the same thing.

[1] https://en.wikipedia.org/wiki/Ostracism

China is famously very accepting of all ideas and would never ban or ostracize members of its own society for perspectives that disagree with the majority's belief.

Yep. Definitely a western thing.

Cancelling finds its roots in the freedom of association.

Cancel culture isn't that either. Cancel culture is a rebranding of 'shunning', which I bet predates humans as we know them. I bet our social monkey predecessors had such tactics figured out.

Read this and tell me it isn't 'cancel culture': https://en.wikipedia.org/wiki/Shunning#Overview

Bonus: 'shadow-banning' is stealth shunning: https://en.wikipedia.org/wiki/Shunning#Stealth_shunning