Eh..... I can't agree, Black Elk.
Pretty much every quality you mention here is true of silver as well, after all. Further more... its mysticism is *hugely* diminished in a world where literal magic is highly present and visible already.
Different currencies and different denominations are an interesting and fun feature as part of world-building and lore in any space, and this is true in D&D games as well... however, this is counter-balanced by the video-game format. In a video game, there is a certain benefit for streamlining elements of minutia that don't necessarily add to specific story being told, and currency minutia is often one of those elements. Within the scope of a video game's story, forcing the player to handle various denominations of currency in a direct or meaningful way will usually end up just being busy work or annoyance (and light knows, BG3, and larian design, has enough of THAT already), but having it handled automatically in a smooth or seamless way that the player doesn't interact with doesn't really *add* anything in this format... so working just in gold is pretty normal as a result. The neverwinter games, for example, just used gold, and weren't the worse for it.
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That aside... the gold *costs and values* that we work with in game should reflect the world space that we're playing in, and they should feel grounded and sensible, and that's something Larian definitely needs to work on in a big way, and onthat score i do agree with the OP's sentiment.