It is clear that Harry and Draco have in no way become friends by the time we meet them again in the epilogue of the Harry Potter saga, nineteen years later.
The term “friend” is an exaggeration and greatly inaccurate. Tolerating would be much more adequate. Indeed, they seemed like they could tolerate each other.
Instead, see their attitude when they see each other on the station platform during the epilogue. Not exactly friendly, shall we say.
“Look who’s there. Draco Malfoy, a dark coat buttoned to the neck, was with his wife and son. His forehead was starting to recede, which accentuated his pointy chin. The young boy looked as much like Draco as Albus looked like Harry. Seeing Harry, Ron, Hermione and Ginny watching him, Draco gave them a curt nod and turned away. » – Excerpt from Harry Potter and the Deathly Hallows
Both of them had now become adults, so they were, logically, more mature and felt a little less hostility towards each other.
JK Rowling will confirm in an interview that these two did not become friends after the war, because too much had happened between them before that.
“Lona: Did Draco and Harry lose their animosity towards each other after Voldemort’s death? JK Rowling: Not really. There was a sort of connection, in the sense that Harry knew that Draco ultimately didn’t like being a Death Eater and couldn’t have killed Dumbledore; similarly, Draco felt gratitude, albeit grudgingly, towards Harry for saving his life. However, true friendship was out of the question. Too much had happened before the final battle. »
In fact, it’s fortunate that JK Rowling didn’t make them friends at the end of Deathly Hallows. It’s also fortunate that she didn’t do it in the dastardly Cursed Child either.
After all, why would they suddenly become friends?
Let’s not forget that Draco Malfoy fought for Lord Voldemort until the end. Only Narcissa’s actions saved him and his father from Azkaban prison.
Let us not forget that he always showed opportunism and cowardice. During the final battle, he will not hesitate for a single second to threaten the trio in the Room of Requirement. Then, he defended himself pitifully against a Death Eater who took him for an enemy.
“I’m Draco Malfoy, it’s me, Draco, I’m in your camp! Draco, at the top of the stairs, begged another masked Death Eater to spare him. Harry stunned the Death Eater as he passed. Malfoy, suddenly beaming, looked around, searching for his savior, but Ron punched him through the cloak. Malfoy fell backwards onto the unconscious Death Eater, his mouth bloody, stunned. — This is the second time we’ve saved your life this evening, you abominable fake! Ron asked. » – Excerpt from Harry Potter and the Deathly Hallows
Why should Harry forgive him or even trust him? He had no real reason to believe he had changed. Draco, conversely, had good reason to respect Harry. After all, Harry saved Malfoy’s life twice. What had Draco Malfoy done to earn Harry’s respect?
However, Harry being Harry, the latter was completely capable of forgiveness. So he forgave.
For his part, it is true that Malfoy seemed reluctant to denounce the trio when they were captured at Malfoy Manor. However, it was not in order to protect them. It was above all because he was more afraid of Voldemort than ever. He especially didn’t want to come face to face with the latter. Since his failure, Draco had become quite disillusioned. Having been spoiled his entire life, he had, in reality, finally understood that life was more complicated than what he had been used to.
Because of this, he probably didn’t want Voldemort in power. He was too afraid of him. Not denouncing the trio, implied for him, possibly being able to put an end to Voldemort’s reign of terror. It was beneficial for him. So, he will not denounce them, not because he appreciated them, but because he saw an advantage in it.
Thus, Draco Malfoy was fully aware that Harry had rid his family of the dark and deadly shadow cast by Voldemort. Whereas, even if it was opportunism on Draco’s part and the latter had tried to kill him in the Room of Requirement, Harry had never forgotten that Draco had not clearly denounced him to Bellatrix Lestrange.
The blond wizard didn’t deserve praise for his actions either. After all, his so-called good deeds at Malfoy Manor were quickly swept aside by his attempted intimidation of the trio in the Room of Requirement. He clearly almost undermined Harry’s mission to destroy one of the last Horcruxes. There’s nothing heroic about it. This misdeed will only be compensated for by the actions of his mother.
Certainly, it seems that Draco subsequently turned his back on his family values by marrying the pureblood, Astoria Greengrass, who had herself turned her back on the fanatical beliefs of her own family.
“After Scorpius was born, Astoria refused to teach her son about pureblood supremacy and hatred of Muggles. Lucius and Narcissa Malfoy therefore found their daughter-in-law somewhat disappointing; Family gatherings were, therefore, often fraught with tension.
This change of opinion will probably not have escaped Harry. Which will perhaps impose a semblance of a form of respect on him.
However, as we witnessed with Sirius Black and Severus Snape, it is very complicated to move past childhood animosities and the one between Harry and Malfoy lasted for seven years and was very brutal. Much more than just children’s bickering. So it’s very complicated to forgive and erase. Too much harm has been done.
Over time, their relationship became very similar to that between Remus Lupine and Severus Snape as adults. The latter had indeed managed to overcome the worst, but the hatred, the insults and their shared history were far too great to be ignored.
Even though Draco had grown and learned from his mistakes, his lifestyle and character were not compatible with that of Harry or the others. Besides, it’s not certain that Hermione wanted to hang out with her torturer. Ron and Neville too.
So the term “friend” is way too strong. But one could say that “cordial understanding, without too much animosity” would probably suit much better.