I am not so sure that Monotheism was or is necessarily superior, nor inferior, to other Theisms-(such as, Henotheism, Polytheism or Atheism). Monotheism, has been and is still, a different type of Theism, which had and still has, an exclusive and uncompromising focus, on a single Deity.
Monotheism, is NOT, "a relatively young cultural development"-(unless, you choose to go back to Paleolithic or even Pre-Paleolithic times...i.e. millions of years ago). However, if you are focusing your chronological attention on the earliest History of Civilization-(i.e. Mesopotamia, Sumer & Egypt), then your statement is totally wrong.
For example, if there was a historical Adam who lived nearly 6000 years ago, then we have the earliest record of Monotheism. If one fast forwards to the historical Noah-(and his Noahide Laws as related to God), we have a second example of early Monotheism-(circa 3000 BCE). And if we fast forward to the historical Abraham/Ibrahim, we have a third example of early Monotheism-(circa 2000 BCE).
Each of these above mentioned Prophets, were the Founders or the Forefathers of Judaism, which, is probably, the oldest surviving Monotheistic religion in the world. However, what is perhaps less known, is that the Hanif Ibrahimic/Ismaili Monotheistic religion, existed concurrently-(and fraternally), with Ancient and Early Medieval Judaism, for thousands of years.
The Hanifs, were a Northwest Arabian tribe who, unlike the majority of polytheistic Arabians during The Jahiliyyah-(Pre-Islamic "Dark Ages"), steadfastly retained their Ibrahimic and Ismaili Monotheistic Theology, customs and rituals. The Hanifs remained theologically static for thousands of years, until the arrival of Islam in the 600's CE with Muhammad-(who himself, was a self-identified member of the Hanif tribe and was NOT an Early Medieval Arabian Polytheist). The Ancient Arabian Hanifs, were essentially, absorbed into greater Islam, though their Theology, customs and rituals, deeply influenced early Islam.
It is believed by Muslims that The Kabah-(the Cubed building which is situated in the Center of the Great Mosque of Mecca), was built by Ibrahim and Ismail 4000 years ago. Inside The Kabah is a Dark Stone or tiny meteorite that landed in Mecca 6000 years ago during the time of Adam. For Ibrahim and Ismail, the landing of this actual outer worldly stone/meteor during Adam's time, was viewed to be the most appropriate Center for a Monotheistic Temple to serve as its Foundation and Place of worship. Shortly after Ismail's passing, the Kabah gradually became a Center for polytheism and idolatry during the aforementioned Jahiliyyah. However, The Kabah returned to its Ancient Monotheistic roots, through Muhammad-(who, as mentioned earlier, was a member of the Hanif tribe during The Jahiliyyah). Chronologically speaking, The Kabah, was the First Monotheistic Temple in History dating to Ibrahim and Ismail's time 4000 years ago. The Kabah predated The First Temple-(which was built by King Solomon), by nearly 1000 years.
There is, of course, Persian Zoroastrianism. Its Founder, was a Prophet named, Zarathustra-(a.k.a. "Zoroaster", in Greek etymology) who "came of age", around 600 BCE-(or perhaps a few centuries earlier). While it was centuries younger than Judaism, (as well as the aforementioned Ibrahimic/Ismaili based Hanifism), Zoroastrianism's Theology, helped to develop a Monotheistic mindset and philosophy centuries before Christianity and Islam. Zoroastrianism, is an early historical example of Monotheism, but it is a dualistically based form of Monotheism, whereby Ahura Mazda, the Central Deity, is entangled in a constant supernatural struggle with its Arch Nemesis. While the Zoroastrian God does triumph, at times, he has been and is still, unable to permanently defeat its Supernatural Nemesis. Essentially, the Zoroastrian Metaphysical and Moral War is constant. It is a type of never-ending war between Good Versus Evil, despite various battle victories won by their Central Deity.
The image of Fire, for example, has deep Monotheistic roots. There is, of course, the story of Moses and The Burning Bush at Mount Sinai in Egypt whereby God reveals himself audibly and representationally, as an Eternal Fire, who appeared and then disappeared during Moses' initial encounter-(though returning at a later date for the giving of the 10 Commandments to Moses). Every Zoroastrian Temple had and still has, a Fire Alter, which too, has a deep and profoundly spiritual meaning for its worshippers whereby their God is symbolically and also, "representationally" recognized, as The Eternal Grand Being.
So when looking at the History of Monotheism, it is simply chronologically untrue to say that it was a "relatively young cultural development". Monotheistic Theology and ritualistic practices have existed for millennia throughout the Greater Middle East and were very distinct among many of their fellow Middle Eastern, North Africa, Central Asian, South Asian and Mediterranean polytheistic neighbors, for thousands of years.