Isekai authors just don't get it.
Feel-gooderies are fine if they're done right. Write out some stuff. The point of a story is Plot, Conflict and Resolution.
What they do is throw out feel-gooderies without focusing on plot first.
The feel gooderies must feel like a rewarding thing, like if a pirate fell into an enemy ship, but fought his way out bloodied, and in the end, came victorious and got the treasure, that's plot development.
Isekais nowadays just scream:
"Hey big boob girl, you wanna read this, right?"
It's fine to make a self-insert feel good manga, as long as you start with the plight of the main character, the conflicts he face and not 'All's good and well, guys, by the way: here's boobs!'
It's the conviction of the main character, his struggle to become stronger, and that's what other people see in them that makes them want to care and stay with the main character.
Not this generic, "here, boobs!!" BS