I'm willing to bet that this series will become increasingly popular as it goes on, and will eventually be known as a pinnacle of fantasy filmmaking. Like the LOTR trilogy, it is supremely confident in what it is trying to accomplish, understands cinematic storytelling and is executing that vision at a very high level. As
@Parmandur mentioned about half a thread ago, it also is deeply rooted in Tolkien's themes (if not his 'cannon') and is weaving those themes brilliantly into the story.
Another small thing it does really well compared to so much other TV is set up it's mysteries. Sauran isn't revealed just because the filmmakers want to tease the audience, but because it makes sense for the character to be deceptive. We don't know who the Stranger is because the Stranger doesn't know. As knowledgable viewers, we get excited about the possibilities, but for the story, every choice makes sense. Mystery boxes aren't inherently bad, they've just been used so poorly for so long that it's easy to lump them all together as bad storytelling.
I find myself throwing on the LotR trilogy several times a year. I do that because of the craft of the film and it's characters. There is so much depth in so many moments, in so many scenes. RoP is following in those footsteps, a prequel done right.