The Roman Empire surpassed it
I'm not exactly sure when Rome surpassed it. You said "empire" which denotes the third phase of roman government. They were a kingdom, then a republic, then an empire. The empire is commonly said to have lasted for nearly 500 years. However, it lasted much longer, about 1500 to be exact. The empire split into two halves, east and west. The west had significantly less resources than the Greek east, which wasn't extinguished until the 15th century ad, by which time they were called the Byzantine empire.
So yeah, Rome eventually fell... But damn they were around for a long long time.
One thing to keep in mind is that governments fail all the time. Would it surprise you to know that the united states has one of the oldest governments in the world?
In a way, I sort of think we would be better off if our government fell. Of course, that statement largely depends on what came next.
There is a major difference between a governmental collapse and a societal collapse. Rome, in the west, suffered both.
In this modern world it is reasonable to assume that even if our government were to fail, our society could survive.
Some possible outcomes in order of worst to best.
1) ever seen a movie called "the postman?" It's a depiction of a total collapse, federal, state and local governments cease to function and armed bands of militias (war lords) take over. Barring some major disaster (big asteroid, super solar flair destroys all modern technology) I see this as rarer improbable.
2) the federal government collapses, leaving state and local government largely intact, as well as society.
I) the states come together, forming a new constitution and a new national government takes over. (similar to Russia after the collapse of the soviet union, Russia changed governments, but society stayed intact.
II) the states cannot agree and several nations are formed instead of one. (viv la confederacy)
3) the federal and many or all state governments go along with it. A dictator assumes power, of either the entire country, or several arise and a civil war ensues because they all want to be dictator of what was the united states. (perhaps in the model of wheat happened to the British in the movie "v for vendetta.")
If society does not collapse it could be a pretty good thing. Our foreign debts are unsecured, if our government defaults, china doesn't get to repo California. The economy would suffer, how bad just depends, possibly not too bad. And the best result would be that all this debt that our country is in is simply wiped away.