I've been studying the Persian and Peloponnesian wars for history at school for the past year. In it we've discussed individuals such as Pericles who could appropriately assess a situation and utilised Athenian strengths and negated Athenian weaknesses, then there are some such as Alkibiades who was a military genius. We also discussed Athenian advantages such as its strong navy which gave it unrivalled naval superiority. Athens controlled the regional markets in the Aegean and trade between Greece and the rest of the world with the Delian league. At the beginning of the Archidamian war Athens had a huge war chest, plus reserves and regular tribute. It had practically disarmed and enslaved its vassels. It's enemy Sparta was very narrow minded in its approach to war which could and to some extent did take advantage of. They may not have conquered massive parts of Persia but for a long time, despite defeats they had pacified Persia in the region. Athens also had approximately 30,000 soldiers garrisoning both Athens and the empire plus 100s of triremes.
Athens on many occasions tried consistently to remove these so it could die and lose to Sparta and Persia. The Athenian assembly went forth passionately with Alkibiades' ideas of conquest in Sicily but then removed him (the only competent enough guy to execute the plan with any chance of moderate success) which pushed him to advise and help Sparta and Persia fight Athens, all this on false charges. They exiled him after a subordinate who did not listen to him lost a battle and ignored his advice in the final battle of the last Peloponnesian war. They elected Kleon to lead them in land campaigns against Sparta (the country who had an army that couldn't be defeated on land. They taxed their empire into rebellion several times in many key regions such as Lesbos. They over invested and lost a large fleet in Sicily plus a large portion of their army and 2 fairly competent generals and politicians despite many warnings not to invade. There failure in Sicily provoked armed and financial responses from Sparta (and co) and Persia. Athens had 2 coups (one oligarchic and one democratic from the navy) which both caused massacres of competent leaders. Athens intentionally executed and removed 10 of some its last competent generals in the penultimate battle.
Like seriously Athens was propped up express sole hegemony over the entirety of the Greek world and more but it just wanted to die.
I do understand though that there is a lot of debate and interpretation on each point made, there are some omitted parts and the value of many historical sources must be evaluated. This was more just an entertaining interpretation of mine. It is in no way a holistic view and should not be taken as such.
Source: reddit post