Good point. He tends to describe more geographically than of specific places. Although what information he does supply is sufficient to paint grand pictures in the mind. The beautifully crafted illustrations also help.
I think this is a common misconception - it's not overly detailed at all - it gives the impression that a lot of detail must have been written because the language is so rich and sense of place is conveyed so well.
I think this is spot on. I've reread The Hobbit, The Silmarillion and The Fellowship of the Ring this year (partway into Two Towers now) and compared to many of the famous names that followed him, Tolkien is BRISK. GRRM wrote 3 times as many pages of ASOIAF as the entire LOTR saga before you even saw your second white walker.
That said, another thing that stands out to me is exactly this. Tolkien was a naturalist and LOVES his descriptions of where they're walking. The Shire perfectly captures a certain rustic ideal, the barrows out Baskerville the Hound of the Baskervilles, and Moria is oppressive as can be. But huge chunks of the work are essentially descriptions of the scenery as they travel. He is, essentially, the world's best pastoral tour guide, walking thousands of miles with the Companions and sharing bits of history, poetry and song about everything along the way. But beyond that... the swords and clothing and meals that later authors tend to fetishize are comparatively lightly drawn. I think this makes the book feel like pretty dense reading despite the overall rapid pace of events.
As to how it would fare now, I think less well. In some sense, I think LOTR was the right time and place. After the carnage of WWI trenches and devastation of nuclear weapons, the old fairy tales Tolkien loved were beginning to look antiquated and not up to the real "monsters" of modernity. What is Grendel in the face of human nuclear power? In that sense, LOTR was perfect in preserving that ethos by removing it from Earth in a way literally nobody had ever really tried to do before (and arguably has been unable to do since). But I don't know how Tolkien's naturalist writing would register in an instagram world.
Also, I'm increasingly convinced LOTR is the weakest of his 3 major works. I think Silmarillion shows him at his most comfortable... writing what amounts to epic poetry of the battles of the gods and unfortunate mortals caught up in them and describing the sprawling, shifting borders and kingdoms rising and falling alongside them. The Hobbit, as a tiny slice of life out of that world, has an adventurous snappiness and a charismatic lead. LOTR, to me, never quite feels comfortable. His vision of "more hobbit stories" demanded by his publisher became essentially a prelude to the hobbits meeting Strider at the Prancing Pony, where he began to try melding the epic tone and sweep of his Silmaril saga with the happy-go-lucky hobbits. I'd say the results are mixed, most noticeably in pacing. It takes as many pages to reach the Prancing Pony as it takes Sam and Frodo to cross Mordor, and the scouring of the shire feels just as awkward at the end as some of the "long walk in the country" does early on.
Finally, there's no way this pitch would work:
"So they get trapped in a tree!"
"How do they get out?"
"This guy Tom, who lives forever and has total resistance to the ring and sings Raffi songs and is otherwise a mystery, rescues them by singing a song to the tree."
"Well... ok. Where do they go next?"
"Into the barrows where they get trapped in a barrow"
"I see... and how do they get out of this one?"
"Tom comes back and saves them again with another song."
"Thank you for your time Mr. Tolkien, we'll be in touch."