I think it's important to take it case-by-case. Many people with ADHD find stimulant medications positively life-changing. However, plenty of people with ADHD also have a substance use disorder. Sometimes medication is an effective treatment for both issues; other times it exacerbates the latter.

Consider the subreddit r/stopspeeding, a recovery community for people addicted to stimulants. Many, many users share similar stories of being prescribed a stimulant medication for ADHD, then beginning to abuse it. Many of these people really do have ADHD, but find that their lives are better without stimulant medication.