I got diagnosed late as an adult and was on ADHD medication for a year or two. It allowed me to actually get things done in my work and personal life like paying bills on time, making appointments, setting up retirement contributions, and filing work paperwork on time. Being able to sit down with the intent to do something and just... do it... was something I never experienced before. It was very much akin to getting glasses the first time after not knowing you needed glasses.
I did worry the stimulant effects of the medication led to me daydreaming "fanciful" ideas that I questioned whether I would have found as profound if not on it. And my wife felt that it made me "snappy". But otherwise I found it helpful and the benefits well worth the side effects.
Why I ended up going off the medication came down to the inconvenience of filling it monthly culminating in not being able to get it. I don't know if it's like this across the USA or just my state (or just how my doctor's office did it?), but I was required to obtain a handwritten/hand-signed paper prescription chit from my primary care provider every month. I couldn't get 90 days' supply, I couldn't use the Pharmacy drive-thru when filling it, and my wife couldn't pick it up. I had to physically go in the doctor's office and pick up a piece of paper with a scribble on it and physically go in the pharmacy to fill. Even medicated, remembering to do this every month is challenging for a person with ADHD.
It came to a head when my primary care provider hired a new office worker whose job it was to be a middleman between the doctor and managing prescriptions. There ended up being some sort of communication breakdown and my prescription chit wasn't ready, then the doctor was out, then I thought the middleman guy was reassuring me he was going to get it taken care of by Friday, but he was actually telling me I needed to get it taken care of before Friday - something like that. By that time I had run out a couple days before, and as often happens with Murphy's Law, it was going into a long weekend due to a holiday so it would be four days before the doctor was back.
I ended up going through cold-turkey withdrawals which were pretty awful. By the time my doctor's office was open again, I was fed up with everything. I had already gone through the worst of the withdrawals by this point. Instead of restarting the medication I decided why not just finish getting over it and never have to deal with this again.
Even though I don't take ADHD medication anymore, I still feel like the experience of having once been able to know what it's like to be able to sit down and pay bills or get boring work done still helps me. It's harder now, but just knowing that it is possible to do is like the difference between seeking a scientific discovery you don't know if it exists versus trying to engineer an experiment you know what the outcome could/should be.