Even though the Eternal Empire of Asurya was a High-Level Civilization and a fairly powerful one, they were still pretty inferior to most of the High-Level Civilizations, mainly due to their small size.
Most of the High-Level Civilizations and High-Level Star Nations controlled at least a few Galaasxies and Dwarf Galaxies and some other types of celestial bodies, so their territories were huge and vast.
Their population was many times bigger than that of the Eternal Empire of the Asruya. Thus, the Empire was somewhat inferior compared to the different factions. The room for development was crucial, but at the same time, the Phoenix Empire was a relatively young nation that had barely been old for a few centuries.