>>356056
The real issue with post Sword Art Online isekai is not being generic, it's the constant use of deus ex machina.
Having one in itself is not an issue, great works use the trope too, it's how it's used and how many times.
In post-SAO isekai the main character
coincidentally find a super powerful piece of equipment,
conveniently unlocks a powerful skill,
by chance stumbles upon the main female romantic interest.
In Inuyasha the only similar thing would be Kagome actually meeting Inuyasha rather than, say, Sesshomaru.
In Digimon Adventure (1999, a "one-way isekai") the deus ex machina is being saved by the digimons in the first episode; every other power up requires a great effort both from the humans and the digimons. In fact, Matt (Gabumon's human) required a whole ass arc to finally unlock his stone's power.
I could go on forever, but that's the thing about post-SAO isekai.