I always hated gods of magic in a game where arcane and divine magic are different things and even more so if the god of magic was the source of the arcane.
I can see a god a magic forming but magic should predate them they just stabilise it or make it more accessible
@Mind of tempest, you mentioned earlier that you dislike tying Psionics to the Far Realm, saying that WotC doesn’t do that to the other magic types. But they kind of do. Primal Magic is obviously connected to the Material Plane, Elemental Planes, and Feywild. Divine magic is generally tied to the Upper Planes. And while WotC has focused on the Aberration side of psionics a lot in 5e, that’s not the only source of it (Psi Warrior Fighters, Soul Knife Rogues, Astral Self Monks, the Telepathy and Telekinesis feats, the Kalashtar). The Astral seems to be a source of Psionics like the Far Realm is in base 5e lore. And WotC explained their reason for changing the Gith to Aberrations quite well, IMO. It’s because they want to fold all Humanoid monster stats in 5e into the NPC stat blocks or change their creature type to one that fits better. They explained that they’re specifically tying the Aberration creature type to creatures from or changed by the Far Realm. They decided Aberrations fit better because of the Gith’s lore of being created by the Mind Flayers, probably the most iconic Far Realm Aberrations in D&D.
I also disagree with the notion that a Githyanki would be offended by being called an aberration. They’re an alien people from the Astral Sea that lives on the back of a dead god. They’re extremely xenophobic and have innate psychic powers. They consider themselves better than all the humanoid races and wouldn’t feel a kinship with them, even if they might be distantly related. Not all aberrations are related to the Mind Flayers or are evil (trust a flumph). WotC didn’t turn the Gith into Aberrations to make it okay to kill them on sight, they wouldn’t do that to the Githzerai.
I don’t like the Forgotten Realms style Gods of Magic, but I don’t have anything against the core concept of a Deity of Magic. The execution is more important to me. While I have more of an Eberron approach to religion than the Forgotten Realms (gods not confirmed to exist, belief is the source of divine magic, religions are more nuanced than typical D&D churches and cults), my current world does have a God of Magic that is thought to be the source of all magic. But they’re also not just the token “Magic God,” and are also the god of knowledge, wisdom, enlightenment, dreams, prophecy, and so on. It is thought in this setting that all magic comes from the Astral, the plane of thought where belief, skill, and devotion can shape reality, the domain of the god of magic (well, it’s more like they think the Astral is the half-dead mind of that god. Long story). So in the main religions, Psionics is believed to be the highest form of magic due to its proximity to the Astral, followed by Arcane and Divine, then Primal (impure magic tainted by the material world), and finally Unholy (fiendish and shadow magic that comes from the Archons). They have this “Hierarchy of the Magics” for complicated lore reasons, but to simplify it a bit, the religions are about gaining divine knowledge (Gnosticism) and Dharmic-style enlightenment. The religion doesn’t like the natural world or fiends, so they dislike magic that comes from those sources.
I think Gods of Magic can absolutely work. I just think they have to not only be Gods of Magic (Mystril/Mystra) or just have it tacked on to their portfolio (looking at you Corellon).
