My personal pension has dropped near 7% of late. Fortunately, I don't need it so it can just sit there and hopefully recover. Swings and roundabouts as said, it's earned at an average of around 5% over that last 20 years so I'm not complaining.
Of as much concern to me at the moment is the exchange rate to Euros as my pensions are in sterling.
One point I don't recall having been made is diversification.
Hopefully it can reduce troughs (unfortunately peaks too) but primarily it means you can pick and choose what to withdraw from at any given time.