The length of Navia's story quest isn't fixed. It depends on factors like your gameplay speed and the paths you take. Some players finish it in around 4-5 hours, while others might take longer.
As of now, the Genshin manga is not finished. The story is still evolving and there's more to come for fans to enjoy. The creators are taking their time to develop a rich and engaging narrative.
There's no definite answer yet. It might continue if there's enough demand and the creative team has more story to tell. But it could also stop if they feel they've completed the story arc.
There is a Genshin Impact manga available. It brings the game's world to life on the page with beautiful art and engaging storylines. It's a great companion to the game.