Was the god YHWH (Yahweh or Jehovah) created by the ancient Israelites or by some other more ancient people?

Historical evidence (including the writings of the Hebrew peoples) is pretty compelling evidence that "God", the god of Abraham, was once one of many other gods in a panoply of gods in the regional polytheistic beliefs.  So, the god of Abraham was not invented by the Israelites (hebrews, or whatever term you want to use for the eventually  Jewish peoples), but was simply taken to be the supreme god, and eventually the only god that mattered, and then the only god.

Why else would god (reportedly) need to say that he is a jealous god and that you should not worship other gods.  That would be unnecessary if the other gods were not gods. It makes no sense to say "do not do" some thing when it is not seen as possible to do.  Not even worth saying.

Yahweh was the God of the Israelites and Samaritans and would also become the God of the Jews after the babylonian exile.

Before the Babylonian exile there was no such thing as Jews, and a lot of them had previously been Baal worshippers.

However after the Babylonian exile Jews, Samaritans and Israelites would become synonymous with each other.

The Jews were not the original Yahweh believers however. The Samaritans believed in Yahweh before the Jews. The Samaritans claim to be the original Israelites. Though today Samaritans are considered second class Jews.

The Samaritans once almost got wiped from the earth during a genocide campaign.

More awareness should be brought regarding their plight.

https://en.wikipedia.org/wiki/Samaritans

There were no Israelites when it was created as Israel had not existed yet.  It was based on ancient Semitic tribal lore, which could easily have been based on some other ancient tribal lore.