Some sources say that in 2015 70% of projects fail to deliver on time, within budget, or to deliver the scope that was expected.
Think of the impact you would make if only 50% of your projects failed in these categories. You would have a 20% increase in benefit, (and you would still have a failing grade overall.)
Getting your projects done on time matters. It has an impact. Either positive (if they are finished) or negative if they keep on sucking time, energy, and money.
Finish on time – always.