Essentially...yeah, I'd say it's necromancy, if you're taking a really broad view of necromancy. But among many religions, ancestor worship is common, with shrines to the beloved dead, and you ask them questions, or they help you with spells...is that, too, necromancy? Because a lot of it is white tablecloths and nice glasses filled with holy water, and not what people typically think of as necromancy.
Latin America still has a lot of influence from the Spiritualism movement of the 19th-ish century, and I personally don't *really* think of seances and spirit boards as necromancy...but they also...essentially are. If working with the dead is necromancy, then that stuff is necromancy.
I grew up practicing Santeria and Vodoun, and while in Santeria specializing in talking to the dead is its own thing and you're supposed to build a nice little separate area for offerings and stuff...no one thinks of it as necromancy. In vodoun, the dead are the ghede and they are EVERYWHERE, can come into any ceremony, at ANY time, and eat anyone's offerings. They are the tricksters. They have the best dances. They're the most *lively* of the spirits. It's all very interesting stuff.
All of that said, I *never* used a ouija board growing up. It just wasn't a thing that people did, because the vibe is so--different? from talking to the ancestors with coconut pieces and whatever. I make myself a ouija board for fun one Halloween, well into my late 20's. It was fun, but nothing mind blowing happening either way. It definitely "worked," but my spirit contacts were all very silly (and likely ghede).
I also don't really think of myself as a necromancer...though I no longer formerly practice the religions I grew up with, so I do this solitary witchcraft thing that involves lots of hanging out in graveyards...but just because I work with a dead god (or loa--technically not a GOD GOD but like a saint, sort of, but really kind of more than that, too--translation is tricky), I still don't actually do much with the dead themselves, so...is that necromancy? No idea. I don't really mind either way. I wear a lot of black and too much eyeliner and have a third of my head shaved, so why not.
Lots of Asian religions are also really heavy on the ancestor worship, and arguably some of the rituals are necromantic, but it's still not what people mean when they say necromancy. It just depends on what paradigm you're working in. But I think that if you use the broad definition of working with the dead = necromancy, and OH BOY, the world has a *ton* of necromancers in it, and most of them aren't at all concerned that they're following a dark path or anything... because its very normal.
Anyway, sorry for the long answer! I just wanted to give a different cultural perspective.