For PPL it doesn't really come into play.
Once commercial there are several regulations and insurance stipulations that require a certain amount of IFR time.
The change to the public transport single pilot IFR rules a few years back stopped a large number of what were low hour air taxi jobs for cpl/ir holders I think you need 500 hours IFR or something like that.
Its a pain actually because these log books don't have a sole instrument flying column. When you apply for your ATPL one of the experience requirements is flight with sole use of instruments. And the only truthful reply for most folk is "I don't have a clue"