The conclusion that there is no evidence other than the structures themselves of a prior civilization's tooling, documentation and equipment means that a prior civilization could never have existed.
An argument that could equally be applied to the 4th AE provenance. (No documentation tooling or equipment).
If they were to apply the above argument to Goblekli Tepi, then they would conclude that the Goblekli Tepi builders had never existed. (No Documentation, tooling or equipment).
The fact is we do not know who the Goblekli Tepi builders were. Which is at this time fully accepted my mainstream archaeology and which understandably is the only acceptable conclusion at this time.
However uncomfortable some may find it, we don't know. We are in a state of not knowing. We are without knowledge. It's a Mystery.
We do know that the 4th AE existed. We also know that according to the mainstream archaeological record that their tooling and equipment was not commensurate with the construction of the GP.
They were a very typical early bronze age society. No more, no less.