Language probably predates Homo Sapiens as our close relatives such as Homo Neandertalensis and Homo Denisova also had adaptations for articulated speech.
Beside, populations today that have never had agriculture or traits we associate with civilization and who live secluded, like the North Sentinelese, all have languages.
I think it’s best explained by environmental factors, rather than something interior to humanity. After all, most of human’s existence was during the Pleistocene, but all recorded history is within the Holocene (except now we’re entering the Anthropocene). Many modern studies account for the climate shifts to explain the development of agriculture: