The toughness of poverty can create the kind of people who can conquer or amass territory to create an empire, but eventually the cycle of empires culminates with the downhill slope, and once again, the poor guy gets stuck with the blame.
The next Persian king after Darius was either Cyrus's other son and heir to the throne or some Magi from outside the royal line.
The Ionian Revolt was not a high priority for the Persian Empire, as evidenced by the fact that King Darius needed to be reminded of it multiple times at dinner, according to Herodotus.
The story of Alexander the Great's Persian campaign, including the fall of Persepolis and his gradual Persianization, as well as a brief history of the Persian Empire's founding by Cyrus the Great.
Cyrus, the Persian conqueror, initiated a strategy of mercy and tolerance towards the defeated Lydians, which eventually earned him their loyalty and service.