There are some comprehensive lists of Roman and Greek gods and goddesses in Gregory Flood’s Lists of Roman Godds and Goddesses.
These were people who didn’t mess about, if they found themselves without a handy god for any occasion. They just made one. There’s a god called Scabies, ffs. (of Itching, in case you wondered).
How did we get from the complex and changing pantheons of the Greeks and Romans and Vikings and Yoruba and Egyptians and indigenous Americans, etc, etc. to the dull God of Abraham? (That’s a rhetorical question.)
There’s an analogy between loss of diversity in species and loss of diversity in beliefs. As humans have shaped more and more of the environment, more unique and colourful species tend to give way under human pressure on their habitats. So, we see the lowest common denominator species prospering. The rat, the cockroach, the pigeon, the housefly all doing very well. (Basically all grey and able to live on s.ite.)
Pantheons reflect a human-centred worldview – a capacity to look for patterns in the universe and human society and to express our innate capacity for transcendence. The list of available gods can be revised in an ongoing basis to accommodate new ones when the old ones don’t work. Human rulers were happy to promote themselves to Godhood, whenever they felt the need.
This suggests that many people were aware that their religions were human constructs but could square this with the social and psychological benefits they got from their rituals. Compared to this, worship of one God seems willfully unsophisticated, and leads to inherent logical contradictions and a need to smite the ungodly.
The one God has expanded to take over the mental and social space we have for deities, dominating whole societies and lives. As far as I can see, this represents an flattening of mental diversity, as when one species – that can live well amongst humans whether we like it or not – replaces the variety that could co-exist in a more fertile environment.