#unless your gods are extremely active in managing how they're worshipped culture is going to shape their perception.

[prolibytherium]

There's a LOT of things people do wrong when constructing fantasy beliefs in pantheons of gods, but one of the more specific is having only one god related to fertility and it kind of being just a horny sex thing.

Like you'll have one in the entire bunch whose sphere is listed as fertility and it's basically like Yeah this is the sex one. She's always depicted naked (but not TOO naked because censorship and/or the writer's own skittishness). She's going to have the exact body type epitomized in contemporary western beauty standards and there's usually no chance in hell that she's gonna be fat (unless MAYBE they're referencing 'venus' figurines). Her thing is fertility, which means having sex and making babies. Might be a goddess of beauty or love or marriage too, because these are kinda sex things, but that's probably it. And yeah that sort of thing is virtually nonexistent in real life.

Like the concept of fertility is so fundamentally important to the function of most societies in human history in ways that it is just Not in industrialized imperial core countries. Most people are getting food from stores, and not having to worry about harvesting crops or breeding livestock or foraging for food or having enough animals to hunt, so fertility only really comes up as a concern if you're trying to have kids (and there is certainly societal pressure to have children, but your wellbeing and survival is rarely going to Depend on it). And I think writing only from that perspective and not even trying to learn about WHY fertility is so conceptually important is why you see this trend.

There's no absolute universal statement about how people believe in gods but it's broadly accurate that systems with many deities will Usually have more than one deity associated with fertility, and these associations will certainly include human reproduction but also the fertility of livestock/hunted animals, plants, the land itself.

Some fertility deities may also be heavily associated with seasonal changes or environmental factors that agriculture or foraging is dependent on (spring/summer/fall, seasonal rains, seasonal flooding, rain itself, sunlight, good soil, rivers, wetlands, etc). Some certainly might be related to love, marriage, sex, and beauty, but that's VERY RARELY going to be the sole way the concept of fertility is embodied. And they'll often will have other associations not directly about fertility, or related to fertility in culturally specific ways.