Two reasons egypt couldn't stop the decline of its 3000 year old civilization

The reasons for the decline of Egyptian civilization were many from among two are these:

Geographical situations: Egypt is surrounded by desert and at that time it was a difficult task to establish strong trade ties with other nations as it was difficult to travel to the place, making the trading relationships not so strong to serve for a long period of time.

Natural disasters and lack of able leaders: Pepy II was the last leader who could pull it all together even during the Nile flooding and drought. There were many who challenged the kings after him and lack of administration coupled with civil war and wide spread starvation played its role. The economic situations were destroyed ultimately resulting in the fall of a great civilization.