The planet is actually made of psychedelics, not stimulants.
spice is both. it also lets you see the future, bend spacetime, and recover the memories of your ancestors. Among other things.
It only lets you bend spacetime in the David Lynch movie.
It’s explicitly described as allowing spacetime bending in the books, maybe Villeneuve will talk more about it in the nexr movies
Spacefolder ships use the Holtzman effect to bend spacetime. Computers were used to find safe routes before the Butlerian Jihad. Without computers, guild navigators use their prescience to find safe routes. Spice doesn’t allow spacetime bending, just navigating through bent spacetime without a high fatality rate from flying into stars.
psychedelics also “let you” do it (and by that i mean make you feel like you can)
I mean yes but you also have to remember that in dune the powerful horny men are controlled by a galaxy spanning religious order of powerful horny women.