Oh, the reasons are many. If you are in your 20s and think that you have had enough of the old jungle saga, first in the form of series and then in the form of consolidated movies by Disney, then you are mistaken, my friend.
(courtesy: express.co.uk)
For example, despite having watched the Jungle Book adaptations whenever there was one, and despite having learned all the songs and important scenes by heart, there is a lot about this animal fable which is unknown and hidden. For example, there are not many who know that the author of the Jungle Book is not an Indian, but an Irishman who came to India just like his other mates on the colonial expedition. That this author, named Rudyard Kipling, was very much fascinated by Indian culture, and religions and traditions here, is evident from his novels like Kim.
Anyhow, let’s not digress from the point and talk about the work instead of the author.
Netflix is here with a series entitled Mowgli: Legend of the Jungle, and yes it’s a must watch, no matter how many times you have watched the Disney movie. The first and foremost reason behind this is that Andy Serkis, the director of this CGI created series, has explored many unexplored layers of the fable which you might have missed as a child.
The trailer itself tells you how different it is from the earlier adaptations of the same book:
Washington Post in its review of the series wrote:
“Intense, dark, muddled adaptation of ‘Jungle Book’ tales.”
It is much more intense and much darker than the other adaptations. See the trailer of 2016 Disney adaptation of the Jungle Book:
Don’t you feel the difference between the two? How did a sweet adventure story from children transform into a story of the exploration of the self with many tragedies and miseries to be dealt with on the way!
While the Disney adaptation has a child of a certain age as Mowgli, played by Neel Sethi, the Netflix adaptation, as is evident from the trailer, traces the growth of Mowgli from a boy to a man. And not just a man at that –a human, searching where exactly he belongs.

(Courtesy: vance.nl)
In Serkis’ adaptation, it’s the inner dark fears showcased inside out. You can feel the underlying ugliness and cruelty of both nature and the mankind peeled and put before us in this series. Surely, the earlier adaptations were primarily for children and hence most of these themes hidden. Netflix, on the contrary, has always had the teenagers and adults as its target audience and therefore has adapted the story from a different point of view.
“Moreso even than the film's violence and suspense, what sets Mowgli apart from other versions of this animal fable is its moral contradictions”, wrote Michael O'Sullivan for Washington Post.

(Courtesy: indianexpress.com)
The creator of the series had the audience in mind who would be nostalgic, owing to their childhood memories of a fun and adventurous animal fable, and who would be struck by the contrast and another layer opened before them.
So it is for this complete view of the story, one must watch this series. Even the trailer tempts one to start with the series right away. No wonder it has got 85 percent rating from the audience on Rotten Tomatoes.