Ugarit was a wealthy port under Egyptian and then Hittite influence, trading with Cyprus, the Aegean and Mesopotamia, and it was destroyed early in the twelfth century BCE in the collapse that ended the Bronze Age across the eastern Mediterranean. It was never reoccupied.
That is why so much survives. The archives were baked hard in the burning of the buildings that held them, and nobody dug them out afterwards. The result is a snapshot of one city at one moment, including letters written in its final weeks, and it is the reason a religion practised across the whole Levant can be known in detail from a single site.
The language died with the city, so Ugaritic has no descendants and no later stage, which makes it a clean witness to how West Semitic religion looked before the first millennium. The gods named in its offering lists, El, Baal, Athirat, Anat, Yamm and Mot, are the gods the Hebrew Bible argues against by name, and the divine assembly, the storm imagery and much of the poetic vocabulary are shared between them. Reading Ugaritic beside biblical Hebrew changed the study of both, and the atlas records this language as the principal reason its Canaanite entries can say anything at all.