Each chapter of the Archon Quest tells us a story about the nation we’re visiting, but I also think it tells us something about the larger picture — what’s happening in Teyvat as a whole.
Mondstadt tells a story about a corrupted dragon, whose tears can only be purified by the Traveler. Liyue tells a story about a god faking his death, and therefore ending all of his contracts. Inazuma tells a story about civil war, and the price of keeping a nation enclosed in a bubble for its protection. Sumeru introduces us to Samsaras, and tells a story where everyone is trapped inside a never-ending dream, doomed to repeat until the host can be woken up. Fontaine tells a story about deceiving the Heavenly Principles to circumvent a prophecy caused by sin.