Typically, we divide genres tidily – if a thing involves magic, it’s fantasy, even if we divide it up into high, low, urban, dark, and so on. Likewise, we look at stories of a futuristic setting and it’s pretty much either science fiction or space opera, with some edge cases. Occasionally people try to work out what would happen with magic in a modern setting, but anything that gets passed off as magic in a future setting is almost certain to be some kind of super-science that follows Clarke’s Third Law (warning: TVTropes).
What doesn’t seem to get explored very often is the question of what happens if a society that utilizes magic starts to experiment and explore the capacity of magic to act like science. Sometimes this makes sense to some degree – in a world where magic needs living creatures to use it and everyone has a human lifespan, there will be a great deal of effort spent on teaching each new generation the same old things, so any progress ends up painfully slow and innovations are likely to be hoarded within enclaves. Even there, though, I’d expect to see some sign of progress over time – people taught basic spells to help daily life as a matter of basic education. A spell that can snuff a fire can save lives if everyone knows it, after all.
Others have magic as a willful and dangerous thing by itself, ready to backlash and destroy people and places; you get wizards who are essentially walking unshielded nuclear reactors. A world like this, I’d expect to see advances in mundane technology relatively steadily, just because the people need an alternative to the man in the pointy hat who might explode in demons every time you ask him for help. Over time, wizards would end up specialized researchers in heavily fortified laboratories, with the more useful non-thaumaturgic knowledge used to help deal with catastrophes. t’d be a lot like nuclear power in the real world, ‘d think.
On the other hand, a world with deterministic magic laws and no need for a living creature to channel the power should see an explosion of magical technology at some point. It’s inevitable that some wizard would work out that they don’t need to do all the hard work of the basics over and over when they can just build something that does it for them. In this, it doesn’t matter if there’s other methods – the easiest method of technological development is the one that ends up prevailing. If you have science, arcane magic, and divine miracles, the divinity is likely to lose out over time unless the miracles can be pulled down without needing a living person. Science, if it has a high entry bar, will lose out against magic if anyone can master the basic functions and easily build from there.
From that point, it becomes only a matter of time before we get a technological revolution with magic at the center, and then we get into interesting questions like what kind of pollution industrial magic might produce, what side effects result from overexposure to thaumaturgy, and what arcane science can do to advance the world. Eventually you get a world that has some similarities to ours, in that a prosperous middle class develops and merchants give way to corporations devoted to producing raw materials and transforming them into finished goods, but it may also diverge widely.
Once they begin to be able to industrialize, if we use the D&D magic system as a basis, you get cheap personal enhancement gear; soon enough every sheriff and police officer has a belt that makes them stronger, tougher, and more agile, amulets that give them tough skin, rings that protect them with arcane force barriers and let them regenerate, and shoes that let them run faster. They have merciful weapons that reliably let them subdue criminals no matter how violent they get with them, and a collapsible door that leads straight into an extradimensional jail. Courtrooms get imbued magic that makes lying incredibly difficult and a jury comprised of summoned creatures of manifest law and justice compelled to pass judgement on those captured.
Merchant caravans get enchanted with levitation and flight spells, letting them cut down time between cities. Every household gets a room enchanted to keep goods cold, a counter that produces cooking heat on command, and a trashcan that devours anything tossed into it after an hour or so. Eventually, everyone has a flying carpet and gets the news via summoned entities. Golems eventually replace labor everywhere – they’re tireless, reliable, and don’t have wants or needs other than occasional maintenance. Only a small part of the population needs to be employed in the tasks of making things, most information-oriented employment is better handled by magic, and so you get a burgeoning population of people with the free time to study magic and experiment.
Eventually someone decides to seal a vessel, enchant it to fly and be full of air, and makes it beyond the atmosphere of the world. They land on a moon, and then soon you have colonies, fortified with magic, spreading across the moon and linked to the planet by teleportation gates. Not much longer goes by and they start colonizing other planets, sending summoned creatures as probes and using scrying magic to learn more about them. Once they learn that other star systems exist, divination lets them fling entire colonies across interstellar distances, while sealed colonies with artificial ecosystems launch into the void. It’s a Von Neumann spread on steroids, with lightspeed a trivial barrier. Extraplanar spaces become targets for colonization as well, with advanced thaumatech cities appearing across any landscape that isn’t instantly fatal. Lichdom becomes a method of preserving the wisdom of the past and extending the research life of scholars, with vast archives of knowledge available even more reliably than the Internet.
And there we get a science fantasy setting; armed with enchanted weapons that are trivial to acquire, adventurers go exploring strange places with the kind of equipment that a typical D&D adventurer would kill for, looking to explore and tame new lands for their people, dealing with exotic new forms of life, and facing challenges that would make demigods tremble.
All in all, it seems like the kind of game that might appeal to groups that like high power and wide-ranging campaigns, possibly even to the point of going to invade the homes of the gods and claim even those exalted lands in the name of mortals.