The remarkable thing is that the rise and fall took a very long time so you can't point to a particular moment of the fall.

> The only predictable parts of life, for the most accomplished court poet of Italy in the fifth century AD, were corruption, a lack of accountability, and a collapse of the constitutional willpower needed to solve large-scale problems [...]

This, and worse - Rome very obviously rotted from within.

The article fails to even mention the most obvious symptoms - Rome's civil wars, revolts, rebellions, ...

Vs. the long, long list in reality: https://en.wikipedia.org/wiki/Roman_civil_wars