The collapse of the Maya civilization is a complex and multifaceted event that is still not fully understood by scholars. However, there are several factors that are believed to have contributed to the decline of this once-great civilization, including:
Environmental degradation


The Maya civilization was heavily reliant on agriculture, and they practiced a form of agriculture that was very intensive and required significant inputs of labor and resources. Over time, this led to soil erosion, deforestation, and a depletion of natural resources, which made it increasingly difficult for the Maya to sustain their way of life.
Climate change


There is evidence to suggest that the Maya were affected by a series of droughts and other environmental changes that occurred around the time of their collapse. These changes may have made it even more difficult for the Maya to sustain their agricultural practices and could have contributed to food shortages and other problems.
Political instability


The Maya civilization was made up of a number of different city-states, each with their own rulers and governing systems. Over time, these city-states became increasingly fragmented and engaged in conflicts with one another. This may have weakened the overall structure of the Maya civilization and made it more vulnerable to collapse.
Social unrest


There is evidence to suggest that the Maya were also experiencing significant social and economic upheaval around the time of their collapse. This may have been due to factors such as overpopulation, resource depletion, and political instability, which could have led to social unrest and conflict.
Disease


Finally, there is some evidence to suggest that the Maya were also affected by a number of diseases, including smallpox and other infectious diseases, which may have further weakened the population and contributed to the collapse of the civilization.
Overall, it is likely that a combination of these factors, along with other, less understood factors, contributed to the collapse of the Maya civilization.