I’m not the first person to interpret the Lord of the Rings with an emphasis on the post-apocalyptic nature. However, I have not seen the story imagined as as taking place within our own future, Planet of the Apes-style. It’s plausible to construct a frame-story for the Lord of the Rings where the seemingly-magical/fantastic elements have scientific/sociological/technological explanations. Let’s take a few of the specific cases.

Races

Why are there different races? Humanity was just beginning the gene-editing revolution. Some teams focused on preparing humanity for our future as a spacefaring civilization. Other teams focused on lengthening the human lifespan. Early experiments in the latter category produced successful results, though with sterile offspring. Further progress led to a viable species, with various races represented among the population. In addition to the baseline men, these additional experiments, in order, led to Dwarves/Hobbits, Wizards, and Orcs/Elves. Orcs, being the darker-skinned members of this final group, have been segregated long enough to develop a distinct culture from the elves.

Wizards

What do we know of the magic of wizards? Gandalf really does seem to be quite the impotent wizard. His wizardry consists of such things as reading books (a rather scientific thing to do), launching fireworks (gunpowder is not such an advanced concept, especially if you are one of the few people who spends time in a library), fighting a Balrog (potentially a pre-arranged stunt), escaping Orthanc with the help of the Eagles (we only have his word to go on here).

Saruman, who has worked together with Gandalf, also knows how to use explosives, and puts them to great effect at Helm’s Deep.

Particulars

“Would you look into the mirror?”

Galadriel has a powerful persona, and if she has access to hallucinogens, combining that with the power of suggestion could account for the visions the main characters see.

Ring Invisibility

Bilbo potentially has help from Gandalf to pull off his famous party trick. Misdirection is nothing new to magicians.

Eagles

This theory deals rather nicely with the Eagles Problem. There are no Giant Flying Sentient Magical Eagles. Gandalf tells stories about them in an effort to perpetuate the myth of magic and wizardry. Sam, having grown up on tales of the Eagles from Gandalf, believes in them in a way not entirely dis-similar to modern belief in angels. Upon destroying the one-ring, Sam sees an eagle while trying to navigate his way out of Mordor, and is inspired to try to follow it, to safety, North Star style. In later retellings, the story becomes more and more elaborate, to the point where they were carried out of Mordor by flying eagles. Why didn’t Gandalf suggest having the eagles dive-bomb the ring into Mount Doom? Because there never were any such eagles.

Narrator

Finally, keep in mind that we are told these stories from the perspective of unreliable narrators who apparently do believe in magic, and interpret events in light of their beliefs that these things are true. Thoughts? What else fits with this interpretation? What things can’t be explained under this narrative? There’s lots more ideas to develop here.