I think the only good thing about these pointless clone isekai manga is that it's the perfect way to teach up and coming writers to create clear major plot events in the story before you put the pen to paper.
You can have as much content in between milestones as you want, but you need to constantly be building the foundation towards that goal. That's the way that you write good stories like Moon-led Journey, One Piece, and Mushoku Tensei.