Why did Rome fall?

Historians have been debating for years about the reason of the fall of one of the greatest empires on Earth, the Roman Empire. However, even today, there was no definite conclusion reached, so there are still many reasons and speculations about why Rome came to it's final and definite end. Some historians believe that Rome fell because of it's geographical positioning. Because of it's shape and size, Rome needed a lot of soldiers and resources to protect itself against the barabrians. Another theory is that Rome fell ebcasue of the economic decline, and inflation. Despite the growth of government, and army, Romans kept importing luxury goods, causing a major fall of the economy. Starting with Diocletian, the government of Rome kept on growing, causing much more corruption, civil wars, and murder of the emperors. It is also speculated that the empire fell because of the decline in the work force. High death rate among the Romans increased, and the number of slaves dramatically decreased. Also, in Rome, there was a lack of technology. As the army, government, and empire grew, there were fewer workers to produce the demans of the empire. Rome had very little machinery that would make human labor more productive. Finally, Rome could have fallen because of the military defeat; the army was no longer strong enough to beat the barbaric tribes that kept on invading.
Personally, I believe that the main reason for Rome's downfall was the fact that invaders kept coming in. The barbaric tribes kept growing larger, and many of them, including the Vandals and the Huns had many invasions on the Roman Empire. Even though the Roman army kept fighting, the barbaric tribes eventually won. Despite the economic disaster, and the government decline, I do believe that the invaders were the ones who caused the Roman empire to fall. The economy and the government would have probably been restored, if a powerful, strong leader/emperor took the power. However, after Constantine's death, that never happened, and the invaders took advantage of Rome's many economic and political issues.