The reasons for such a move include power outages in Tehran, which developed into a full-blown energy crisis late last year due to aging infrastructure, sanctions, and Israeli strikes. Other factors include overpopulation and water scarcity.
Another possible factors for the shift in capital could be for reasons of regime stability. The recent collapse of the Syrian Arab Republic, was caused in part by uprisings in and around the capital city of Damascus, which was far from the Assad regime’s coastal support base around Latakia. The Islamic Republic may wish a capital city more politically secure.
Security concerns might also contribute to the decision to move the capital, due to successful recent Israeli operations in Tehran. In July, Israel successfully assassinated Ismail Haniyeh, Hamas’s political leader, while Haniyeh was in Tehran for a presidential inauguration.