I believe they are merely tribal or national variations on a pre-existing God. The Romans were impressed with the Greek gods and adopted them wholesale, changing their names. Zeus became Jupiter,etc. I recently asked about Mecheldizek and his legitimacy as a priest. It seems that basically the same god was worshipped in the region. Abraham starts the line of Jewish gods. YHWH, I am what I am, denotes a god who will not name himself. Naming in these cultures was common in adolescent when personality traits emerged. The baby name was replaced with a real name, often indicating your traits.
I can see how YHWH became impt to our civilization. Jews-Christians-modern society. Maybe He just survived and the others faded. There may been political and social religions for Judaism lasting so long. It is so, so much older than Christianity. The origins of YHWH are murky, pariticularly in the Bible. YHWH does not strike me as the same God who sent Jesus. Jehovah does not remind me of Christ. Vengeful, wacko, blood thirtsy, arrogant, presumptuous, jealous vs. love and grace and mercy.
No one knows.IMO. B/c what did God do before Abraham. There is Noah and other occasional figures but no national group. A New York Times article discussed archaelogical finds in Israel. When Israel was first established, archaeologists flocked there with Bible in hand, convinced they would excavate the details in the OT. They do not exist in large measure. If these places existed, there would be some trail present. An example is the flood thread. Science shows no global flood. Now archaeologists are more detached. Present thinking is that the Bible was commissioned by a powerful later King of Israel. In order to legitimize his rule, he commissioned the Bible. The references to distant figures bind him to the Jews. He wanted legitimacy on a grand scale. Solomon's temple can't be found.
I am writing from memory. It may be false. The gist is what I wrote. Food for thought.