Function and expression of pseudogenes
A subset of pseudogenes can have a function - even if not translated: For one possibility see the official record for PTENP1, which acts as a tumor suppressor by providing a decoy for PTEN targeting miRNAs
A subset of pseudogenes can be translated. There is a selection for preserving the length of the reading frame, which suggests (but does not formally show) the presence of a translation-dependent function of (at least a subset of) those pseudogenes. - See Xu et Zhang 2016: Are human translated Pseudogenes Functional? (paywall)
As indicated by the above, it seems likely that quite some pseudogenes have a function, which just has not been discovered yet - and that the mode of action can differ between different pseudogenes.