> Fascism is to cancel others with opinions different to yours.
No. That is not what fascism is and using the word like that saps it of all meaning.
This is what Fascism is: [1]
> Fascism (/ˈfæʃɪzəm/ FASH-iz-əm) is a far-right, authoritarian, and ultranationalist political ideology and movement that rose to prominence in early-20th-century Europe.[1][2][3] Fascism is characterized by support for a dictatorial leader, centralized autocracy, militarism, forcible suppression of opposition, belief in a natural social hierarchy, subordination of individual interests for the perceived interest of the nation or race, and strong regimentation of society and the economy
As others have said, one can reasonable debate whether Yarvin should be identified as a fascist or "merely" an authoritarian monarchist. But either way he advocates for the replacement of democracy with an oppressive authoritarian system, is in a position of some influence and power, and is an enemy of anyone who values a free and open society.
If you're not familiar with the Paradox of Tolerance, you should look it up. [2]
> The paradox of tolerance is a philosophical concept suggesting that if a society extends tolerance to those who are intolerant, it risks enabling the eventual dominance of intolerance, thereby undermining the very principle of tolerance.
There is a valid argument to be made that if we want a free, open, and tolerant society we can not tolerate those who publicly argue against that. We don't have to throw them in prison, but they should be "de-platformed" -- boycotted in all public spaces. Their authoritarian ideas discredited and ignored. That's what the parent comment is referring to. And that belief -- that certain ideas that threaten a free, open, and tolerant society should be discredited, de-platformed, and boycotted -- is in no way similar to fascism.
[1] https://en.wikipedia.org/wiki/Fascism
[2] https://en.wikipedia.org/wiki/Paradox_of_tolerance