Well, that was in the past. Mistakes were made. But now, with modern theories and Science, we, The Warriors of Light, have finally figured out what's right, once and for all. So we can throw out the caution and the epistemic humility to the wind and go punch the baddies. Doesn't it feel good?!

>people ... suggest cancel culture is only something to complain about if you've done / said something wrong

This is an oversimplification. What you might be extrapolating from is the common sentiment that complaining about cancel culture is not substantive in cases where an individual appears to have done something wrong enough to justify the consequences. Yes, "wrong enough" is of varying subjectivity in each case, but focusing on "cancel culture" as some kind of monolithic evil instead of focusing on the details of each case is a very common source of noise, and so is commonly criticized, and that criticism may be what you're accumulating into "cancel culture is only something to complain about if you've done / said something wrong".

Yeah I think it's interesting to think what people of today will be cancelled for. My best guesses are eating meat, and doing business with China.