I’d argue Harry is way worse than both Aragorn and Rand Al’Thor.

That's fine. You're entitled to your own opinion.

What qualities does Harry have?

Naivete, isolation, and confusion that gives way to optimism and comradrie in Book 1. If you ever read any Roald Dahl novels, he's got much of the same youthful curiosity and compassionate cheerfulness of James from the Giant Peach and Charlie from the Chocolate Factory.

Much of Harry's early personality is informed by his struggle to understand his parents and his parents' friends, picking up and discarding their habits and traits in pursuit of self-actualization (Book 3/4/5, in particular, have him latching onto Remus Lupin and then Sirius Black as idols, only to lose them and himself in turn). Over the course of the series Harry's initial optimism is poisoned by cynicism and hatred, frustration at the failure of his elder peers, and ultimately a depressive death spiral. He matures, discarding the childish qualities of the early books and adopts more mature (often toxic and reactionary) views and motivations by the end of the series. As a case in point, Book 1 Harry would have happily joined SPEW, while Book 5 Harry considers it an annoyance. I'd say Harry's arc really peaks in Book 6, when he uses black magic on Draco Malfoy and Snape has to rush in to save him. He's gone from a cheerful, generous, naive little kid to a battle-hardened child soldier.

Like, if I was to really describe Harry's story progression, that's it. Its a look inside a child that's forced to fight a war for survival. You get a similar (abet much better written) character trajectory for the Animorphs. But to say nothing is going on with the central character? That's blatantly rage-bait.

Also my suspicion that book 6 is the last book that Rowling had more than a few token notes on. By book 7, you can really feel the ghostwriters crowding in and WB taking a heavy hand in editing/finalizing (although it's clear they've been around since book 4). Forcing a Disney-style happy ending on a wizard civil war betrayed so much of what Rowling had set up in the early novels.