Listen to the Rain

Maybe they're around because the D&D world is so old? So many lost empires. Sure, you may have a kingdom where each generation makes maybe 10 magic items from all of it's best magic smiths, but throw in a few dozen millenia of that with few being destruction, and also stuff like gods, demons, and so on making their own (Hm, most magic being of planar/magic being origin in a younger world, perhaps?), and they build up.

That's true. It's also possible that any pre-human races had/have cheaty ways of getting around it like the elves do. Their High Magic used to come without any downsides other than the "1 per week, no other spells at all" thing.

One thing I notice is that in D&D computer games, I get way more potions, scrolls, wands, etc. than I ever remember getting in tabletop. Maybe it's just that we always refused to use them because of the megalixir problem.

("You're fighting a red dragon inside an active volcano and you don't want to drink your potion of fire resistance?!"

"What if we have to fight two red dragons later!?! What will we do then?")

Reminds me a bit of Dragaera in Steven Brust's books. All magic from the most common magic (there's a few types- witchcraft, Necromancy, sorcery, but aside from sorcery the rest are rare or weak) involves drawing power from *one* artifact. It cut out once and floating castles starting falling from the sky. But it lacks the range limit like Mythallar, which adds a really cool wrinkle.

Oh, I remember that! It was in that 3 Musketeers homage, right? The Phoenix Guard? Or the one after it?