Judging a pension by how it performs in 2008 seems wrong. Like their main job is to perform well over long periods of time compared to other funds.

Checking this shows that 12 years is longer than 1 year, and thus is a better metric.

well I agree, my point is that ie 2007-2021 is better than 2009-2021, and with my example I meant to illustrate that the best performers will perform less well and the poor performers perform better if you include 2008, showing that this does in fact matter.