Harry Potter was an extremely intelligient and naturally gifted boy who was verbally abused to the point that he thought he was essentially worthless and refused to try in case he got in trouble for it. And despite his many accomplishments such as
- conjuring a Patronus at 13
- teaching a good portion of his school DADA including upperclassmen
- getting extremely good grades in his OWLs without Hermione’s crazy drive or really any real academic drive
- excelling at potions once the abusive teacher is taken out of the question (even with the extra directions that’s still a pretty extreme difference- the extra instructions only help fine tune things)
- many of his teachers referred to him as very bright and aside from Snape (and Umbridge) seemed to think he would go far- BWL or not
the fandom still likes to portray him as dumb or completely useless without his friends, with the only thing he is good for is Defense.
I don’t know what books you read but I don’t think they were the same ones.