Explanation: During the First and Second Punic Wars, Rome fought against Carthage, a power that equaled it in vastness and resources. During the Second Punic War, Italy itself was ravaged, and the city of Rome threatened. Very dramatic, very high stakes, all that jazz.
The Third Punic War happened after Carthage, reduced to a city-state, had already lost an entire army against a neighboring kingdom of raiders. At which point Rome decided that Carthage had illegally defended themselves without permission, and sent a few legions to capture and sack Carthage, destroying the polity once and for all.
... kicking a country when it's down just isn't as exciting as a prolonged life-or-death struggle between two great powers.