Since ancient times, humans tried to find ways to explain the origins and mechanisms of the universe and the explanation and worship of many deities are one of them.
And many mythologies involve many deities or supernatural beings of many kinds - some have even more than one, benevolent, malevolent or somewhere in between.
Some were described with eloborate physical features like having body parts that are found in other animals like Ra and his falcon head or Anibus or winged human-like bulls in Mesopotamia; or have the ability to take shape of something or are a representation of something like Osiris and his green skin or Hel whose half of her body is either dead or old.
But as mythologies and religions evolved, many religions (including ones that still exist today) shifted to the worship of deities that are either nameless or formless but also omnipotent and not exactly specific representations of a certain trait or feat like the Jewish religion, God does not have a specific name because it is too considered as too sacred; or Abramahic religions like Christianity and Islam simply call God as God or Allah with no distinctive name like in previous deities.
So how did this shift in how religions function occur? What were reasons behind this shift?
This question is asked through the lens of religious history as a single progression through time from less advanced to more advanced. What you've done is describe a number of very separate evolutions in completely distinct traditions, and with the advantage of hindsight linked these together with the current Abrahamic faiths as a sort of logical endpoint to this evolution of ideas. In doing so, the vast complexity of religion throughout history is reduced to a single timeline, leaving out much of the nuance that makes history valuable.
Firstly, there's the important matter of chronology. You mention Judaism and Islam in one breath, ignoring the fact that there is more than 2000 years of history between these two phenomena. Even within Abrahamic religions the matter of depicting God was the subject of intense debate. Consider the Reformation movement in Western Europe, where one of the main beliefs of the new protestant religions was that any pictorial representations of religious figures was idolatrous, in stark contrast to Renaissance Christendom where even images of God himself were sometimes made. Similar debates had also raged much sooner in early Orthodox Christian communities.
This demonstrates another important facet in answering your question: today both Catholicism and Protestantism coexist with their own differing beliefs of how (not) to represent God. In the same way, other beliefs than the Abrahamic ones still exist to this day, each with completely differing ideas of how to visually represent their deity/deities of choice. A very clear example that comes to mind is of course Hinduism, a religion still adhered to by almost a billion today that uses a large pantheon of colorful gods just as you describe 'older' religions doing.
Again, there is no single chronology here. Zoroastrianism is one of the oldest known active religions and it famously had a much more abstract and dualistic view of the universe than polytheistic predecessors. This view of the universe as a constant struggle between good and evil would also influence later Abrahamic teachings. When it comes to the history of religion and ideas, it's important to keep in mind that there is no single progression that is followed, but instead many different threads that each unfold in their own unique way and which sometimes connect. Eventually, the prevailing ideas aren't necessarily 'better' or 'more rational' than those that came before, instead it is often a complex interplay of many different social and political factors that lead to the survival or the demise of certain ideas.
That is why it's dangerous to attempt to make sweeping statements about 'the evolution of human society.' In the history of ideas it's easy to be struck by a sort of survivorship bias, as the ideas that have survived the sands of time must surely somehow be the best ones, always exceeding those that came before. In reality, history is rarely ever so straightforward. There is a large body of study into the evolution from polytheism to monotheism in the Levant and its later spread to the Roman empire, and it's certainly worth looking into if you're interested in the subject, but until we all become proud Pastafarians there will never be a single evolution of human religion, but instead a complex network of different belief systems that can all influence each other in different ways.