Why does Achilleus predict that the Achaians will drop and die at Hektor's hands?

Achilleus predicts that the Achaians will fall to Hektor because he recognizes Hektor's formidable prowess in battle and leadership. He understands that Hektor, emboldened by his own strength and the support of the Trojans, poses a significant threat to the Greek forces. Additionally, Achilleus feels a sense of despair and disillusionment with the war, believing that without his involvement, the Achaians lack the strength and unity needed to overcome such a powerful opponent. This foreboding reflects Achilleus's awareness of the dire consequences of his absence from the battlefield.