The ephedrine plants would be precursors to stims but still need quite a bit of preparation as far as I know. You might be able to get ephedrine extracted from a plant but that’s not a stimulant in the way we would think of adderall or cocaine or something today, having a more similar effect to caffeine.
Yes. That’s why I compared the two. However when comparing caffeine to what Id argue most people think of as stimulants like cocaine or amphetamine, they have incredibly minor effects. Its like comparing <1% thc hemp and a 90% thc concentrate imo