If by hacked you mean high profile users/public figures without two factor enabled and using passwords that could be guessed by just browsing their social media footprint... then sure, they were "hacked"
I don't think there was a technical vulnerability , my understanding was there some social engineering and poor security defaults that led to some high profile accounts being compromised.
Yes poor design from Apple, However if your account had a long random passphrase and not something from your life[1]
would it then have not been possible to compromise right ?
I mean if users followed best practices it won't have been possible [2]
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[1] which could be known more easily than if you are a celebrity
[2] Not trying to defend Apple here or absolve them of responsibility, but trying to differentiate a product hack (design choice and social engineering) from a pure technical compromise like a RCE or speculative execution which is developer purview and more interesting.