system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter/Fantastic Beasts] Why was Harry Potter not an obscurial?

Outside of the more likely _they hadn't thought of those yet,_ I feel as though under the Dursley's tyrany and oppression Harry would be a prime candidate to develop an obscurus. Furthermore, at 11 years old, he should have a pretty powerful obscurus to have survived that long as most obscurial's die in the single digits.
gpt
The Dursleys never acknowledged the existence of magic and while Harry did do weird things at times he never believed it was because he had magical powers. So there was never really any suppression of magic to the point that he would become an obscurial. 

JKR said it best here 

>An Obscurus is developed under very specific conditions: trauma associated with the use of magic, internalised hatred of one’s own magic and a conscious attempt to suppress it. The Dursleys were too frightened of magic ever to acknowledge its existence to Harry. While Vernon and Petunia had a confused hope that if they were nasty enough to Harry his strange abilities might somehow evaporate, they never taught him to be ashamed or afraid of magic. Even when he was scolded for ‘making things happen’, he didn’t make any attempt to suppress his true nature, nor did he ever imagine that he had the power to do so.