"Everyone in fantasy books is always resorting to the "old magic". Why isn't the new magic better? That's what I want to know," said Obi-Jon (@jonthepo0le) on Twitter, possibly not expecting to get taken up seriously on it. My knee-jerk answer was "because then it would be science-fiction." (1)
Okay, let me expand briefly — and I honestly hadn't thought of it like this before — but is there any system where the magic of now is an improvement of the magic of yesteryear? I would be really interested in any other examples people have. Or where magic is something that people are actively experimenting with, investigating and refining? Actually, there are a few. Juliet E McKenna's Hadrumal Crisis (and its precursor seriesses) shows wizards who are approaching magic with an analytical eye, and attempting to produce new effects through known magical properties. In Sanderson's Mistborn series the very regimented and understood magic is developed by the protagonists — ah, but there it's still a shadow of an earlier age of gods and monsters from which everything in the plot derives, and whilst Rothfuss's Kvothe is an innovator, his shadowy nemeses are proof that his magic is peanuts compared to the old days of power.
And of course the Inapt magic in Shadows of the Apt is the same — it used to be a big deal, and it's basically just dregs at the time of the book (and in fact you discover one reason why in Seal of the Worm, spoilers spoilers spoilers), whereas the technology of the Apt has been improving in leaps and bounds, artificers reacting to the work of other artificers so that the capabilities of the Wasps or Collegium as seen in War Master's Gate vastly outstrip anything that anyone has ever been able to accomplish before. There was no lost age of power that they are trying to rediscover, as is often the case with a magician protagonist. They are making it anew.
And there are SF books where the tech is being rediscovered — post-apocalypse and after-the-fall settings, and of course there are the SF-trappinged fantasies like Star Wars where there was an elder age, now fallen into disrepair (2). But the majority of SF looks forwards to at least the possibility of a superior future, just as we do in modern life. But there was a time when we didn't. Even though there were people actively innovating and making things better all the way through the history of the world, there has also been a very strong meme of any given current age being the least, a shadow of its predecessors. Just as Tolkien's Middle Earth slowly slides towards mundanity through a sequence of gods and elf lords and the like all taking up boating and naffing off until there's nobody left but, well, us, so historically, people have looked back on a lost golden age of heroes, or an antediluvian age before God god mad at us — an age when people were bigger and stronger and lived longer and… oh, everything. It's a mindset that is strongly implicit in many religions, that the arrow of progress basically only goes backwards — then was better, now is worse. That's why some people can use the phrase "the mother of all battles" unironically, when reason suggest that such a scrap would basically be two amoebas bitch-slapping each other.
What you need to be frightened of, given the world of reason, progress and improvement, is the child of all battles.
(1) Actually it was "because then it would be science fiction. Discuss" because I'm pretentious like that.
(2) And an artifact of the order the movies were made in adds to this impression — the prequels are far more high tech than the originals.