Sporadic, restricted use of amphetamine tends to retain full effect over the long-term. With regular use, the subtle change in perception it causes tends to persist longer than the physical stimulation. The appetite issue can sometimes be addressed simply by actively choosing to eat more.

I do think that, in the long run, it at best averages out between the unavoidable highs and lows. Some people benefit from being able to time when those periods happen. Probably net loss in many cases. Still, the behaviour you're describing represents the end stages of escalating use and loss of control where they have fallen into dependency and/or addiction. That's not inevitable. Some people do seem to be able to self-regulate their use of strong stimulants.

But you're right. It's clear some people are just innately more driven. In the worst case they're like Elon Musk, always flitting around, perpetually alternating between chipper and enraged, and always with coffee in hand and at most four hours of sleep the night before. I find such people infuriating, but that is probably just envy.