Harry Potter didn’t really have anyone to turn to and that’s why when it comes to his relationship with Sirius Black, it is so important to both the series and fans.
Sirius Black didn’t have anyone and neither did Harry Potter, really. They were two people who lost the one who cared for them the most and when they finally found each other, it was exactly what they needed.
When it came to Sirius Black, he was thrust into prison for something he didn’t do and then was forced to hide in the darkness when he did escape because the world thought he sold out Lily and James Potter. At that same time, Harry had ran away from his aunt and uncle’s before coming back to school and was feeling just as alone.
The two finally, throughout everything, found each other and were finally able to be there for one another in a different way. While the Weasleys took care of Harry, it wasn’t the same because they had their family. But Harry? He didn’t have anyone and neither did Sirius. Which is why, to me, the two worked best as family.
Sirius Black missed his best friend and Harry was his last connection to that and Harry didn’t know his parents and wanted some connection back to them. Thus a beautiful relationship was born and, at the end of the day, these characters cared about each other and it is beyond sad that they didn’t get to spend more time with each other throughout the series. They came into each other’s lives and then Sirius was gone.