Hashem gives us a chance to get it right

Adam had three sons one of whom died.

The line of Kayin ended with Lemech who had three sons, one of whom created weapons that were used for death.

The line of Sheth ened with Noach (son of Lemech) who had three sons. The curse of Kena'an can be attributed to his father Cham and can be considered "like" death.

The line of Shem ended with Terach who had three sons, one of whom died.

It can be considered that he finally "got it right" and produced progeny that were able to resist the idol worship that had taken ove the world. Of his two surviving sons, Nachor had twelve sons, eight by his wife and four by his concubines. Avraham had Yishmael and Yitzchak.

Yishmael's line is given at the end of Parshas Chayei Sarah and shows twelve sons. Nothing further needs to said about them.

Yitzchak had Yaakov, who had the twelve shevatim, 8 by his wives and four by the "servants" of his wives. While he considered them wives as well, they seem to have considered themselves more like concubines.

It should be pointed out that "concubine" was a legal status and is not the way we would consider it nowadays.

This brings to mind the medrash that Hashem offered the Torah to all the nations in the world before giving it to us at Har Sinai. It appears from the history of the worls, that every lineage had the chance to reach the level of Avraham, but failed. Once someone finally "got it right", the Torah follows that group to see if they can manage to continue on the right path.