alt Hacker News> maybe I should find ways to spend my time (careers, hobbies) that work well with that
You're really close to getting it.
Students in school do not have this flexibility. They are required to be there, an 8th grader has no control and little influence over how their time is spent, or whether their tasks are a good match for their abilities.
So the only option in school is accommodation. There are some who continue to expect that into adulthood, but the vast majority of kids diagnosed with ADHD do not seek accommodation in their professional life.
Why? Because they do exactly what you propose. They find careers that match their disposition.
This is an important distinction. Indeed, many behaviors (ie attachment issues) that are maladaptive for an adult can be adaptive to a child and it is important to not change those without taking into account the environment a child is in.
An 8th grader may not have control over how their time is spent, but an attuned response from the people around them will help the child adapt.
A child experiencing: 'everyone around me can take this test, but i cannot, I must be dumb'
vs
A child experiencing: 'everyone around me can take this test, but i cannot, I must be dumb' and a caring figure in their life explaining to them 'you show traits of ADHD, this commonly makes it harder for you to focus on things like a math test. it really hurts when you fail the test and you wanted to get an A. Why don't you try again at the same problem at home, I believe in you. And maybe I will talk to your teacher about some extra time for the next test. We can't always get this, and even if you don't pass the test it's ok.'