@oscarjiminy the conclusion echoes criticisms I've made of ADHD (and neurodivergent) characterization: so much of it is defined by what assessors think is a problem, not what the individual being assessed thinks is a problem.
My brother and I were both diagnosed with ADHD as adults. Looking back, the evidence was all there when we were younger but because neither of us "acted out" or noticeably struggled academically it wasn't brought up. Even the name, attention-deficit hyperactivity disorder, is biased towards the impact it has on others. My problem isn't that I lack attention, it's that I lack of control of attention. Sure, that makes it harder to concentrate sometimes, but it also means I miss meals or don't sleep because I can't interrupt myself. Not staying on task is what teachers care about though, so it is what gets focused on.