Dio was just lucky.
- Son of a drunkard. Beated daily.
- Dad of Jonathan took him in, gave him a nice place and an education.
- Ultimately Dio acted like a little bitch and went against Jonathan.
- By mere chance did Dio find the mask.
- Dio loses everything after a long battle.
- Dio, again, by mere luck, manages to kill Jonathan, gaining his body (And stand. It was not his).
- Dio gets killed. This time for good.
There is nothing amazing about Dio. All the stuff he had, or did, was because he lucked it out.