The problem is the tests are all so subjective even when conducted by a psychologist.
I think how a person will answer them, even when they que trying to be honest, will vary wildly depending on lots of factors that have nothing to do with ADHD or depression or whatever, such as self leniency, expectation, how long they've lived with their symptoms, coping mechanisms in place or crutches.
I mean "How often do you have problems remembering appointments or obligations?": yeah I guess you could just let your life go to shit, but many ND people actually OVERcompensate for this trait by having very detailed planners, alarms, calenders so in fact they never have trouble remembering. If they have been using these for a while, they would answer "Never" to this question.
"When you have a task that requires a lot of thought, how often do you avoid or delay getting started?"
So, procrastination. A classic human trait, and in fact isn't actively NOT delaying tasks that are hard more unusual?
"I find it hard to remain focused in group settings" and "I often miss what is being said to me in conversations"
Could be ADHD I guess, could also be social media-enhanced narcissism, see also the rise of polarised debate, echo chambers, etc.
It's like those tests they use to check whether you're depressed. "I find it difficult to take pleasure in activities I used to enjoy" - Maybe you're depressed, or maybe you're just bored with life.