Yes, fresh prunes do have a subtle sweetness.
While often associated with dried prunes, fresh prunes offer a more complex flavor profile. They possess a sweetness balanced by a rich, earthy tang, making them less intensely sweet than their dried counterparts. The texture is jammy and appealing. As one source described, they are "not too sweet, not too sour, not too sticky, and not too dry." This balance makes them a versatile fruit for eating fresh or incorporating into recipes.