Depending of the commutation rate, not taking a lump sum could be a bad choice.
I recently took a pension lump sum of 25% tax free with a commutation rate of just under 21 – in other words for every £1 of yearly pension I sacrificed, I received a tax free amount of £21. Had I not taken the lump sum, after paying tax in the annual pension income (at 20%), it would take me over 26 years before the annual pension payments exceeded the tax free lump sum. For someone retiring at 65, they would need to live into their 90’s to win out.