I often criticize the attempt to define something by what it is not. For example, it’s illogical to define “red” by saying “a primary color that isn’t blue or yellow”. However, when people keep consistently missing the point and abusing language and meaning, sometimes it’s necessary to do so.
“Polytheism” is the religious regard for, and acknowledgment of, many gods.
Polytheism is not reductive, even if paired with a cosmology or philosophy which holds to a belief in a singular substance/source of all things (e.g. a divine vat of Playdough or the Big Bang or a festering corpse from a giant llama that died before creation and from which sprang All), because Polytheism is a -theism, not a random #-ism. It isn’t Polyism, it is PolyTHEISM, meaning that it is a religious consideration centered around the gods; it is by and large disinterested in things which are not the gods. That doesn’t mean that those other considerations are null and void (such as examining other things which are not gods, such as grains of rice, agriculture, horticulture, sex with a blender, or a festering llama corpse hung from your child’s basketball net) but rather that they are not part of a Polytheistic lens of consideration and discourse. It turns out that being a Polytheist doesn’t prevent one from also drinking coffee (protip: Folgers is not a god) or operating machinery (also not gods) or going to the post office (definitely not gods). Similarly, there is room in some Polytheisms for a substance monism. But that is not in and of itself a Polytheism, nor is is particularly relevant in the consideration of Polytheistic theological or practical “things”.
Polytheist religion is also not atheistic academic banter, or debates about mythology, or post-Christian writing. Those would be, just like Folgers and festering llama corpses, OTHER things.
There may be intersections between considerations of many gods (Polytheism) and other-than-theistic considerations (such as Folgers) but that doesn’t make the one into the other. That makes them an intersection.
Similarly, that two gods share a syncretic relationship does not make them one god, although a single god may in fact spring from such syncretism… which, in such a case, would mean a third god, not the loss of the initial two (or more).
Polytheist religion is expansive and even exponential; it is inclusive, rather than restrictive and reductive. It is relational; that is, it is about relationships between things (plural, many), and not about the reduction of these relationships into smaller numbers of things. The models of the individuality of the gods — and their relationships to us, and ours to them — are similarly apart from relationships with other things (such as coffee, coffee companies, and spirits).
Polytheist religion has spirits, some of whom may well also be gods, others of whom descend from gods, others of whom host the gods within themselves, just as we humans and human-shaped-creatures sometimes do, in process of possession. Some are ancestors or wrathful dead, others are quirky personalities residing in objects the secular world might consider inanimate. In this way, Polytheist religion often overlaps, or runs alongside congruently, various animist understandings.
It is about many things. Not one things, not some things, not an ever reducing number of things.
If you don’t like math, that’s okay: you’re not required to count.
Polytheist religion cannot be counted; it is too big to count.
So if you like math? Fantastic, there’s lots of math here. Don’t like math? Great! Stop trying to count all the things. It is often enough to acknowledge that there are many of them, and that they exist, and that you may (or may not) know and count some of that many. (Example: I like coffee, but I do not like Folgers coffee. That does not mean that Folgers coffee does not exist, nor would it be sensible to assume that my coffee, being coffee, is the same as Folgers coffee, which is a different sort of thing entirely. Further, my taste in coffee may not be congruent with others, because our universe has many tastes in coffee. I do not need to know all the types of coffee to acknowledge that there are many of them; I gain little in attempting to count all of the types of coffee, and similarly, my failure to properly account for every specific type or expression or taste of/in coffee does not invalidate them, nor put them in contest with other facets of reality.) Attempts to negate the many (gods, coffees) by collapsing them telescopically into less many is bad math. Stop that.
Stop doing bad math in the name of religious discourse.