>>715147712
An objectively underbaked (And bad) aspect of the series is Stark, he was supposed to be an exploration of the tank/frontline stereotype, but the author half-assed it and sort of just relegated him to comedy relief + forced romance for fern.
There's plenty of things to complain about, but almost always, it's people complaining about things they missed the point of, that's my issue.
Hyper-developing the world wouldn't have added anything to it, because fundamentally the story is about Frieren dealing with the realization that she needs to appreciate time and the people she spends it with. The series is about her slow character growth in that regard. The first episode shows you she doesn't even begin to have a glimmer of this idea until after the 10 year adventure is over. And it doesn't even hit properly until Himmel's funeral.
But what is also relevant to the series is magic, the demons, and mana, which is why effort is put into developing them.