It's literally the most "Arab" Maghrebi state. Probably because of its heavily desert environment even along the coasts it was substantially settled by Arabian tribes like the
Banu Hilal and
Banu Sulaym during the Middle Ages whom Ibn Khaldun b-words and moans about in his writings because of their barbaric pillaging and how they swarmed the region like locusts, rofl.
Anyway, I used to run a lot of genetic models on Maghrebis and always noticed Libyans seemed the most clearly "Arabian" admixed. Some of these saaxiibs can look like 60% or more Saudi/Negev-Bedouin, last I checked.