In sefer 'Divrei Yitzchak' it points out Moshe took out from Eygpt an Eruv
Rav of peoples from a multitude of nations worldwide who over the years
had been enslaved there in order that they would eventually return to
their nations and testify to the Oneness of Hashem and the wonders he
performed on behalf of his holy people.
In addition to the reason - so they won't be able to claim: " had we been
given the 613 commandments we would have done as good or better a job than
Israel." The same reason they had Bilam, " had they a prophet as Moshe.... "
We see that at each trying moment -such as when they miscalculated the 40
days Moshe was to be on Sinai, the Eruv Rav questioned everything to that
point and cast off the yolk of heaven which limited bloodshed, belief in
power independent of Hashem, and relations with multiple and prohibited
partners. These other nations who did not have The merit and refinement of
Israel were unwilling and unable to become Torah Nations.