Answer:
Akbar was one of the most just and peaceful emperors in mughal history. Although he did engage in military endeavors, he tended to avoid military conflicts.
However, rulers afterwards him were expansionists and wanted to expand the empire even more. Because of this, they started an unending war with the Hindu Rajpuths in the South.
Moreover, the imperial treasury went through difficult times because of building the Taj Mahal (the construction cost was massive) and because of the tax policies.
Further more, as the empire was massive, most of the rulers after Akbar was not able to administer such a vast empire.
Administration problems, issues in tax policy, religious policy problems and issues related to diplomacy were the main problems the other rulers were not able to face properly.
Step-by-step explanation: