what you have to remember is that for all the main kinds of ND diagnosis there is a set criteria, a minimum thresh hold that you have to meet to get a diagnosis.
I have been through both as an adult for myself, and as a spectator/mum for both my kids.
All 3 of us have AuDHD, but all 3 of us are very differently affected, but we ALL meet the threshold for diagnosis.
My son is the most significantly affected, he also has Dyspraxia and an eating disorder because of it... he has higher rate PIP, needs full time care, despite seemingly intelligent to talk to (if he'd talk to you, he's selectively mute with strangers).
My daugher is Demand Avoidant, but very animated, chatty, and her ADHD hyperactive brain is horrendous.
My Autism is quieter, i have more sensory issues, my adhd is inattentive, but i will monologue on favourite subjects.. which i switch regularly XD, i've never held a job down, have had more therapy than i care to mention to help me cope with crippling anxiety and am a functional depressive with a caffeine problem (dopamine seeking) i tried medicating my ADHD and my Autism took the wheel and turned me in an unstable wreck.
The each have their criteria, they need to have been present from childhood, and impact your life significantly.
The fact society likes to self diagnose is watering down the impact of the diagnosis. the fact women who weren't diagnosed as kids because the criteria was based on male presentation means there is a surge in women and girls being diagnosed, its making people think 'everyone' has it. They don't.
if you don't meet the threshold, you don't get a diagnosis, its that simple, and they criteria are not a low bar.