Of course you were wondering. In that little bubble you inhabit, no officer ( of the useless variety ) has ever been posted sideways into one desk job after another until they reach the 16 year ( pension ) point, and then quietly disappear. ( There is certainly scope for civilianising those desk jobs )
Does the same thing happen ( with useless ) OR's ?
If the answer is no. Then @bob231's assertion is absolutely correct. There is a major issue with a career structure that holds onto ( until pensionable ) useless officers.
The difference between useless officers and WO1's & WO2's, is that while some are absolute c**k's, very few of them can be regarded as useless, or they would never have reached the rank of WO1 or WO2.
** With the caveat that the R.Sigs might be totally different from the rest of the British Army.
For really important events like the state funeral of Churchill, the Senior Service is called upon to do the big parts like pulling the gun carriage. The rest of it is like the motto of the NAAFI girls "they also serve, those that stand and wait".