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

Thus, the Unforeseen emerged, namely the new monotheistic faith, at a time when the religious map seemed complete and tightly shaped. Islam was the response to the religious, social, and political quests of the Arabs, managing to inspire in the Arabs of that time what Christianity and Judaism failed to achieve...

This not by the expected choice of one of the existing monotheistic religions, but with the unexpected introduction of a new monotheistic faith, overturning the existing conditions and relationships at all levels.

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