Why did the Arabs of the peninsula not do the Expected and convert to Christianity or Judaism with their strong presence and influence in the region, when they gradually felt the need for monotheism for many reasons of their own?

Thus arose the Unexpected, namely the new monotheistic faith, at a time when the religious map seemed complete and tightly formed. Islam was the answer to the religious, social, and political quests of the Arabs, managing to inspire in them what Christianity and Judaism could not...

Not with the expected choice of one of the existing monotheistic religions, but with the unexpected introduction of a new monotheistic faith, overturning the facts and correlations at all levels.

Islam offered the Arabs what they lacked: universality, their "globalization." The local, regional, and national became global, universal, supralocal, international.