Ok so coffee is made from coffee beans. And beans are *also* made from beans. Why is nobody making, like, black bean coffee?

Why doesn't this exist?

Take dried beans, roast 'em, grind 'em, and brew some bean juice?

I have no idea if it would taste good or not, but we don't know if we don't try.

Edit: I need to see what dried beans I have and maybe go shopping. I will give this a try with a couple different types of beans and report back if I fart or not.