Half the sounds on the record don't come from instruments. They come from the world. A train platform. A broken speaker. The hum of a refrigerator in a quiet room at 4 AM.
Sampling isn't about lifting someone else's work. It's about hearing music in things that weren't meant to be music. You pitch it, you chop it, you layer it until it becomes something new.
Sound design is the same process but starting from synthesis instead of recordings. Both paths lead to the same place: sounds that don't exist yet.