You are largely thinking about the US, which just seems to be more and more politically polarised. The 'cancel' part is not a feature of (left) activism though,

You are largely thinking about the US, which just seems to be more and more politically polarised. The 'cancel' part is not a feature of (left) activism though, it's a general feature of this polarisation - see e.g. the whole 'take a knee' controversy.