In what way are we the barbarians? They were young, strong, becoming increasingly well organized and on the rise. We are no longer any of those.
The barbarians were culturally young, healthy and beginning to understand and use the power of their cultural youth and more importantly, were becoming organized instead of easily defeatable roving war bands with pathetic little chiefs who fought amongst themselves so often almost anyone could conquer them and who spent more time pursuing “blood feuds” with other tribes, it’s amazing they managed to organize at any point in time…
Rome, or if you prefer, the Western Empire, was decrepit, corrupt, riddled with Emperors who felt the entire project existed just so they could enjoy themselves (If golf had existed, the comparison might be even more apt and the Roman citizenry were concerned primarily with their entertainment and how much the current government was going to give them.
The West could not hold on to what it had, yet kept trying to expand and spent its treasure and armed forces in endless, pointless wars of conquest/reconquest with no clear objective when various generals weren’t busy fighting each other over who was to be the Emperor that week or leaving critical border areas unguarded as they raced their legions back to Rome to try to claim the purple…
The Eastern Empire, I think it can be argued, diverged very rapidly from what most people think of as “Roman” and in fact became a very corrupt near-theocracy with the Basileus as the direct representative of “Christ” on Earth in ways the western Popes could only salivate over.
Two centuries or less after the fall of the western Empire, the eastern was significantly different and Marcus Aurelius wouldn’t have recognized it as being Roman I suspect.