The ability to harness fire meant the ability to much better deal with predators, weather, disease, and all of those other ills that were otherwise dealt with by begging for the gods' mercy. Fire means you can now create bricks, weapons, and you can purify medical instruments. You can create agricultural tools to reap better harvests, and you can create storehouses to keep them in. Fire means you can work with stone and metal in ways never before possible, and create things never before possible. Because of this, humans became more buffered against the chaotic forces of nature and could mitigate disasters more readily. They no longer needed to fear the gods quite so much, so I can certainly see why Zeus so harshly punished Prometheus.
Fire is energy in it's purest form. A combustible substance is excited to a high enough temperature and it begins to break down into its base components. As it breaks down, energy is released. That energy is fire, and the fire comes in many forms.
If I trace back from this laptop I am writing on, I see that the cord plugs into an outlet on the wall. The outlet goes to the house, to the pole where it connects to the city's electric grid. This grid connects to a power plant, which may be fueled by solar power, wind power, nuclear power, hydroelectric power, coal power, or possibly something else.
All of these energy sources, in some way, are fueled by a source of fire that humans have revered since the dawn of human intelligence: the sun. The sun fueled the plants' photosynthetic processes millions of years ago which had over time been compressed into coal along with the creatures who ate them, and the creatures who ate them. It evaporates the water from the planet's surface to recycle it back into rain which fills the rivers and turns the turbines on the dams. It heats the planet so that weather fronts can clash and create glorious thunderstorms to set fire to the caveman's stick.
The fire of the ancient sun is literally channeled through millions of tiny channels of wire in this laptop, giving me the ability to scry to anywhere in the world, to know what is going on anywhere in the world at any time, instantly. It has given me the ability to carry a library to rival Alexandria's in my purse. It has given me the ability to discover any fact that I need to know, instantly, and to tap into the great global group mind to ask it anything. With technology that I have in my pocket, I've got a communicator and a tricorder, a navigational system and star charts. It's more impressive than what Mr. Spock carried on him. The technology would make me appear as a god to primitive humans, even humans as primitive as the ones in the 1980's.
My beloved consort, Onix, sums up his magical motto as Clarke's Third Law: "Any sufficiently advanced technology is indistinguishable from magic." Following that back to its start, then Prometheus is also the father of the magic. Most obviously he is the father of the magic of technology, the smartphones and laptops and atomic bombs and medicine have given humans awesome power, the kind of power that would be considered pure sorcery. Nikolai Tesla was often referred to as a "wizard," as are many people who are "computer wizards," or "tech wizards." Though we use technology often, the inner workings of the technology still are an arcane set of secrets, only available to those dedicated seekers who put in the work to seek them.
Ironically, this technology that caused Zeus to punish Prometheus is the exact technology that can help humans to seek the gods more fully. Because I do not have to worry about freezing through the winter or dying from any random cold I catch, I have more free time and energy to spend on exploring the mysteries. Our relations to the gods now can be less driven out of desperation and fear of the unknown, and more out of love and a desire for gnosis.