It seems like you don't quite get it, you watch at AoW universe through your eyes as a man living in real world, when you need to try get perspective of someone living in that fantasy world. "Magic" there is part of physical laws of the universe, if someone in that world sees construct he doesn't think "wow, that's magic", like you when you see robots created by Boston Dynamics don't think "wow, that's magic". So dreadnought aren't magical smith, same as engineers of Boston Dynamics aren't. The only "magical" part about them is that their knowledge about how universe works is much deeper than of "regular" smith.
Affinities in AoW4 isn't just different types of magic, they are fundamental parts of AoW's cosmology. Anything existing in that universe falls in domain of one (or several) of affinities, doesn't matter "magical" or not. Materium and Astral isn't about earth magic and lightning magic, it's about material and immaterial. It's why elementals, even though available for all affinities, generally associated with Materium Affinity, because everything material consist of
basic elements, and elementals are personified manifestations of those elements, while Ethereal is associated with Astral, because ethereals are beings from beyond material plane.
After rereading OP, I think you just don't vibe with the affinity and don't see appeal of it, because by it's concept it's the least "magical" affinity compared to any other. I to be honest love it most and don't see any "identity crisis" at all. You can flatten mountains, call earthshakes, turn things into gold, create material goods out of mana, elevate magma from depth of the earth, animate tools, manipulate winds, create amazing constructs and else. Yes, there could be more stuff about item forging, but original game wasn't designed with it in mind. And I don't see why the whole affinity should be shoehorned into this narrow theme of item forging, when it already covers it, but also several others themes.