Why is Aryan invasion theory disputed by some historians?

The Aryan invasion theory is disputed by some historians due to a lack of concrete archaeological evidence supporting a large-scale invasion of India by Aryans around 1500 BCE. Critics argue that linguistic and cultural similarities between Indo-European languages and ancient Indian texts can be explained through migration or diffusion rather than invasion. Additionally, some scholars emphasize the continuity of indigenous cultures in the Indian subcontinent, suggesting that the interactions between different groups were more complex and gradual than a straightforward invasion narrative. This has led to alternative interpretations that focus on assimilation and cultural exchange rather than conflict.