LordFran, I think what you say is very true, although for me in the present moment, and, I suspect, for most, it's theoretically true more than it is practically true.
With reference to the OP, I want to say yes, it is possible to achieve the same or superior state as that induced by adderal or other stimulants - with some caveats. Those caveats being that there is massive variance already in the baseline state of human wellbeing, and not all of this variance is under our control. There are some states that it is not possible to induce without exogenous help - or at least, they are improbable or difficult enough to be considered effectively impossible for all intents and purposes.
Additionally, not everyone is capable of achieving the same states, for better or worse, whether from genetics, circumstance, previous choices, which when it comes down to it are all the same thing anyway.
I guess what I'm trying to say is - it is theoretically possible for everyone to achieve a state of focus and alertness rivalling that of a hard stimulant without said stimulant - but not everyone, practically, will be able to do this, and it's impossible to know whether or not it is actually possible for you until you actually achieve such a state - and, of course, if it's not possible for you, for your unique brain chemistry, genetics, life circumstance, etc... there's no way really to be sure of this so you may as well keep trying. The benefits of aiming for such a state are immense of course, so even if you try and do not get there you will still be at a better place than when you started.