Are you asking "which historical events led to Afghanistan being called 'the Graveyard of Empires,'" or "what factors led to Afghanistan being a historical "Graveyard of Empires?"

I am not a historian so I don't know if this book is trusted that well, but Afghanistan: A Cultural and Political History by Thomas Barfield specifically addresses this question. Some of the major themes he brings up are the ethnic diversity of the region, the way that Afghanistan has tended to be on the "edge" of empires rather than the center of power, the impact of the Mongol invasion that has since left most of the populace to subsistence farming or nomadic lifestyle (IE absence of a ruling, urban and political class), and an absence of nationalism in favor of tribal or ethnic loyalty.

He comes to the conclusion that essentially, Afghanistan has been "easy to conquer, hard to rule." Larger powers with concentrated capitols or ruling classes come in expecting to take over the ruling class and capital, and find that they cannot extract taxes or support from the local population because their loyalties are to their families, tribes, and ethnic groups that ignore the borders imposed by treaties, as well as have plenty of animosity towards each other. In addition, they don't have stellar wealth or power, they have lives of subsistence farming or are nomads.. these people spend their days worrying about getting food, water and shelter, not nation building.

What Barfield gets at is the idea that Afghanistan has been geo-politically useful to control by foreign powers as well as easy to acquire. However, the nation is largely decentralized and it is difficult for those foreign powers to control long term, they face animosity and violence in the region they wish to control and because they are outsiders, cannot convince the population to work with them (or for them).

I recommend the book, it has a lot of interesting insight into the cultural diversity of Afghanistan and you can learn a lot about the lives of these people, then think about how they're impacted by foreign powers trying to control the region for their own gain. And how a consistent lack of nationality in the region has made it so difficult.

This question was asked a few years ago. The consensus I gathered was that the nickname was inaccurate as several empires managed to hold the region. Here is the thread.