In Deathly Hallows, Dumbledore's seems to put some stock in a person's worthiness to unite the Hallows.
“I was such a fool, Harry. After all those years I had learned nothing. I was unworthy to unite the Deathly Hallows, I had proved it time and again, and here was final proof.”
— Deathly Hallows, chapter 35 (King's Cross)
However, while Harry is undoubtedly the hero of our tale, and a good/heroic person - his ownership of the Hallows is mostly chance -
- Harry unknowingly defeating Draco after his defeating Dumbledore gets him the Elder Wand,
- Dumbledore leaves the Stone to him
- He inherits the Cloak from his parents (via Dumbledore!) as a family heirloom.
Nothing particularly 'worthy' in any of those specific instances, and Harry being the one to disarm Draco in particular is specially chancy.
Later, while Dumbledore calls Harry The True Master of Death "because the true master does not seek to run away from Death." at the same time he also says that the Hallows were most probably unconnected objects created by three individuals and the legend of Death and the Three Brothers sprung up afterwards, indicating that there isn't actually any truth to the whole 'Master of Death' idea.
Additionally, the curse that leads Dumbledore to lament about his unworthiness is an artefact of Voldemort's conversion of the Hallow to a Horcrux and nothing to do with the Stone's 'Hallowness', so to say.
So the question is, is there any canon info indicating whether worthiness (however it's being defined) actually was a factor when it came to owning all three Hallows at the same time and this is not just Dumbledore airing out all his issues with self-worth?
Is Harry being 'worthy' supposed to be have caused chance to make sure he gets all three Hallows?