Executive dysfunction, especially that which was not impairing as a child, has a lot of potential causes. Anxiety, depression (yes, ADHD can cause these, but these can also cause executive dysfunction in people without ADHD), OCD, Bipolar (manic people in particular often attribute worsening of hyperactivity and distractability to ADHD instead of mania), Schizophrenia pretty much universally is related to cognitive symptoms and lowered motivation even when not psychotic, and borderline personality disorder can cause changes in interests and identity.
For many of these conditions, stimulants can act as a band aid on something else. It can superficially make people feel better (of course, it's speed), but it can distract from other symptoms that are impairing functioning, and prevent people from seeking long term solutions.
I recognize that non-medical options should always be front line approaches but there can be a chicken and egg effect as to making that happen.
In my youth I adhered to a "better living through chemistry (wink wink)", I do now too (rip Mitch Hedburg) but the wink wink part is very rare and disciplined and now it's all about pharma and supplements to wring what I can out of what I've got left.
That's not to say I'm not on the medication train (despite moaning about medications a lot). I do personally avoid taking any controlled substances. This is easy because I hate how stimulants make me feel, but in general I worry about the effects of having a direct reward signal from taking a pill.