There’s such a large difference between normal human functioning, which can include struggles, and a condition where those struggles are a problem to the point where they require a psychologist to help.
For example, everyone feels anxious at points but not everyone has anxiety. I’ve been very anxious at times in my life, such around major assignments when I was in school. However these struggles were appropriate given my situation and I was able to get back to my normal life pretty quickly. In contrast, my father was absolutely non-functional for most of my childhood. He literally would not make phone calls because he was so anxious to talk to people. He had no friends, the only people he ever talked to outside of minimal interactions at work were myself, my mother, and his own parents. Medication and therapy turned that around real quick. I’m just a year he was totally normal, had started making friends and going outside of the house to run errands.
There are probably people who are getting therapy and accommodations for ADHD when they don’t need them. But is that really so bad? Why shouldn’t people, even if they don’t have a disorder, get therapy and accommodations to help them succeed?
Overmedication is a different issue, and definitely a real one. But that’s on doctors and drug companies - it doesn’t negate the reality that some people have disorders which need medications, therapy, and accommodations.
I think from personal experience I have a high degree of confidence that ADHD is real. I have a couple friends with ADHD and it is obvious their attention works in a different way - they are sometimes totally engrossed in something, so much so that it’s almost impossible to get them to think about anything else, while other times they are easily distracted. I have other friends who seem normal to me but who say they have benefited from therapy for ADHD, and I don’t see any problem with that. I have observed both of these categories of people taking responsibility for their lives and working to improve themselves, often with the help of therapy but not without their own agency.