Well-crafted artefacts are uncommon. Artefacts made with free methods—you might call these “handmade”—are especially so.
Artefacts made with free methods often have a unique aesthetic quality—especially on the surface—that is hard or impossible to recreate in mass-manufacturing.
Beyond that, two artefacts made by the same person will be different from each other. Even if the maker produces a batch, they will all be noticeably different, especially close up.
These small differences benefit from close inspection by the audience.
If an artefact is mass-manufactured, the quality is usually noticeable enough. Each artefact may be the same, but the group of them will be different from their competitors’.