When the Jinns invaded Cressmont City, the place Artemians chose to be their base of operations, Lucan and his subordinates prioritized escaping. Given the tight time, they only managed to take a couple of their most important equipment and artifacts.
That said, the majority of their research materials were left in the city, as well as some other valuable artifacts. After they were gone and the Jinns had completely taken over, the latter naturally took everything of value.
Since they were a race that didn't focus on research and development, they only picked up the artifacts.
For them, the Artemians' research materials were of little to no value. While there were researchers among the Jinns, they were mostly delving into the development of magic and skills.
