@aleaallee Id rather say its a series, where the author actually gives a fu*k about world building and makes the isekai stuff meaningful.
Basically 99,9% of the other isekai series either just kill the mc off or transfer him in the beginning of the series and never came back to why. 10+ years ago this was just called fantasy story, but now they just add the 3 pages isekai plot to market their product with an "isekai lable", though its just another fantasy story rip off.
I read my first isekai as a kid 20+ years ago, when the term didnt even exist (Neverending story). This story is the first Japanese work actually coming close to this one.
Just finished reading LN. What manga reader won't know about this chapter is
this event take place way far away in the future (like 10+ years away). Lightnovel have quite a strong hint that most of these non-kumoko pov take place in the future and keep you guessing what the heck happened in those gap.