"
Magic's just science that
we don't understand yet." -Arthur C. Clarke
Guess you know more than Arthur C. Clarke ever did.
Keep up the good work, and keep using "the google" for answers.
It is a very adequate phrase, but for our world, in which there is no magic, but we have often taken for magic situations that are scientifically explainable.
But in Eberron it is the other way around. In Eberron, magic exists, and is used extensively replacing technology. Eberron's technology is medieval, but the setting is not medieval, because magic has replaced technology, and puts the setting in a situation similar to our industrial revolution, but in Eberron is magical revolution.
It is not technology, it is magic. In Eberron there are trains, but they are literally driven by lightning, not by steam, not by fossil fuels, but by magic, literally, a magical lightning. In Eberron there are airplanes (or zeppelins), but they are not our planes or zeppelins. There is no technology in the airships, its functioning is through magic, its propellant force is a bound elemental, and its driving does not imply knowing of science or tech, but having a magical dragonmark that connects with the magical rudder of the Airship.
In Eberron there is a telegraph system, but it is not a thing that goes through cables or waves in the air. It is a magical system, which works through
sending spells that work through magical communication stones that only Sivis heirs can handle,
In Eberron we still have a very efficient postal system, but instead of vans, use couriers mounting magically modified horses to make them faster and more tireless, horses that can have magical horseshoes that allow them to walk over the water or even make small flights to evade obstacles. Are we sure that our vans are better than these magical mounts?

The orien couriers do not use airplanes, but use dragonhawks, hippogriffs and similar mounts for flying services. Again, it is not technology, it is magic. And it is not medieval, it is magical. All these magical mounts are much, much more efficient than the animal mounts that we can have in the real world, even in the 21st century.
In Eberron there are cannons, but they are not the cannons of our world that work with powder. Eberron's cannons work with elemental shrapnel (there are earth, fire, electric, ice ...), and energized by an alchemical solution of dragonshards.
In Eberron there are missiles, but they are not our missiles. In the war, in Eberron, a Siegestaff is used, which is a huge magical staff (not thought for adventuring), which allows to cast a magical spell amplifying it in various ways (including distance), by trained soldiers that are not able to cast the spell by themselves but have taught them to use this “high magic artifact” (instead of high technology device)
In Eberron there are no firearms, but there are soldiers fighting with cantrips and wands that are basically magical gunmen. And we are sure that a 21st century war plane is more terrifying than an Audarian soldier on the back of a dragonhawk throwing fireballs and other spells from the air?
Similar parallels could be made with medicine and the hospitals of House Jorasco, which are basically magical medicine.
In Eberron there are industry, but the factories do not have production lines with advanced machines, but the production lines are magical artisans using cantrips and rituals, and when "advanced machinery" is necessary, they are not really machines, but magical forges that require the use of Dragonmak of Making (a dragonmarked Cannith heir!). And yeah, those magical forges are so advanced that they can even produce Warforged, which are much more than robots, are sentient and intelligent organic constructs. Neither our AI of the 21st century equals that.
In Eberron there are theaters with magical items the size of an organ that produces illusory images, a projection system at the level of our best special effects. Do we remember that the illusion magic can even produce tactile, thermal or olfactory sensations? There is even television for the rich, with a magical object similar to one of those balls that the discos have, which takes the live image of the phiarlan artists in the theatre and transmit it to crystal balls linked at the house of rich customers. Hey, is television, but no technological, is pure magic of divination and illusion.
And although Eberron's magic advances in general equals our late nineteenth-century technology, some of the previous examples can be considered more of the twentieth century or even the 21st century. Moreover, some "technomagics" of Eberron have not been achieved in the 21st century. House Orien has an instant teleportation system for the very rich. Only for the rich, because there are not many Orien heirs with the greater dragonmark, but the system exists. Some independent wizards can do the same (not many because there are not many wizards or sorcs with that capacity in Khorvaine, but they exist, and what current transport system can match this?).
It is not technology
. In the words of the creator of the setting, Keith Baker, on Eberron he intended a world where magic replaced technology, and where arcane magic was science. In Eberron, arcane magic is based on scientific principles (you do this, this and this, and you consistently obtain this magical effect), and completely replace our science. There is no mysticism in Eberron's magic, it is arcane science that is taught in universities, schools and artisan guilds.
Also, it is magic in evolution. Eberron is supposed to be in an intense process of magic revolution. Airships, lightning rail, etc, are recent innovations. There is an intense competition between the Dragonmark Houses & the Twelve, Arcanix & the Arcane Congress, the elemental binders of Zilargo and other minor actors to achieve better magical innovations. If a campaign lasts enough decades, Eberron's magic should match our technology of the twentieth century, and even that of the 21st century.
So Eberron is not science fiction. Science Fiction implies the use of advanced technology and science. Eberron is Fantasy, because everything this setting uses is magic. It is not
High Magic, however. It's
Wide Magic, no High Magic (In Khorvaine there is extensive magic use of up to the third spell level, but from there the number of people who can produce higher spell level effects are drastically reduced, and we can no longer speak of extensive use). But it is certainly High Fantasy.
And DDO has only scratched the surface of the setting, and to do justice this game would have to deepen much more.