Very true.
Once you got into the second part of the city (I only played GTA3) and obtained the codes, there was really no incentive to play the story mode (though some of the missions are badass). I almost always end up driving some really fast car till I blow it up, which attract the police, who attract my bullets, which led to more police and, soon enough, helicopters, which led to me grabbing for my rocket launcher. After about 10 minutes, I die.
Rinse and Repeat.
(still fun)