Most substances that have any kind of enjoyable aspect tend to be very bitter and have an alkaline taste. Think of like coffee, we cut it with stuff or sweeten it with sugar. Pure alcohol would taste terrible, thats why we have beer, wine, and spirits. Its all alcohol but nowhere near entirely alcohol.

Also, not all substances are able to be used by your body in same way or with nearly the same level of efficacy. Some things have high bioavailability when snorted, like cocaine, but many things have no bioavailability when snorted (even if they do when consumed orally). Likewise you cant smoke just anything, as not everything can be absorbed through your lungs

That said, sugar and salt are probably the most commonly eaten substances that also jack up our dopamine levels. We just dont think of that as drug use. Spicy food can also be just as addictive, as eating really spicy food releases a lot of endorphins and makes some people feel great. Is that substance use? I think most people would say no, because were also doing it for the flavor. But my nervous system would say yes