The Word "Craft".
Craft is a human concept. We can not imagine going to very distant places on our planet or space without the use of some kind of vehicle or craft.
But that is a reflection of our physical/biological limitations and the result of our evolution as a biological organism.
But that is not a necessary condition for other organisms or beings.
Classical Ufology have implicitly placed a limitation in what can be expected, but the observational data available today clearly indicates that anomalies are entities by themselves, that anomalies can be considered as the "fusion" of the craft and it's occupants that the classical ufology was expecting.
We do not need to be hard pressed to find any "crafts", anomalies are more than that.
As humans we tend to use obviously human concepts, but anomalies are pressing us to think outside the box and many times reject old ideas and concepts.