Thats a fair point. Nothing to argue here about. It was stupid for them to do so.
However, considering how hard is write these sorts of opening I think it’s fine to suspend a little disbelief
Though Its perfectly fine to not like story because of that aswell.
Feel free to skip reading this. It's just me discussing writing in general and not this story specifically. And I am in agreement, enjoy it if that stuff is right in your alley.
I understand the effort it takes to properly do your worldbuilding, ensure your characters are consistent and to properly outline your plot and the end goal you're aiming for. I will say, personally, the most difficult thing to write is dialogue because you need to have it flow naturally, consistently with the personalities of each character involved, not force things unnaturally to get to the result you want, and also not have excessive dialogue that is unnecessary for the story. Characterization and small talk is fine, but it should still ultimately serve to provide additional information in a natural manner that helps to either fuel up the personal dramas, advance relationships, expand worldbuilding, set up future consequences and/or advance the plot.
In general, I have a personal belief that you can utilize some contrivances, some pulled it out of your ass deus ex thing to set something up. But if you're aiming at a well written story, you are also required to heavily limit how often you rely on it.
In the case of Isekai stories. I view it as the premise of an isekai itself being an ass pull. You engaged in something that already sets someone up into a specific circumstance with a specific start for your story that is literally a deus ex machina. You can then work backwards to it, to explain how this happened and make it fit and work within the world building, bring it into relevancy into the main storyline as well. This typically happens because we usually want something close to in media res, where we start off the action with a bang. If we worked forward from the world building to determine how the isekai would function, that would also work but it would be a slow burn right off the bat. It could work very well, but it would require a lot more effort to maintain the attention and investment of the reader.
So generally, that one ass pull of the base premise of Isekai is something I accept and can see being used for both the benefit of the writer and the reader. But beyond that initial ass pull, that the reader has already signed up for due to the Isekai genre. The more ass pulls you take to set up your story by force. The less engaging it becomes. The more it becomes a string of tropes. The less you need to engage intellectually into how you see the story advancing based on the characters, their circumstances and the world they're in.
The lower effort stories are typically what you see collectively refered to as trash. And most people understand that and even enjoy it, ironically or unironically. It is a theme park ride, and maybe we have a few nuggets of gold in there.