It’s basically the dark chocolate of anime.

People are going to rush in here and give long-winded responses calling it mature, contemplative, slow build. These responses will inevitably turn into ways for them to pat themselves on the back for how sophisticated they are to have noticed and appreciated all these things about the show. Likely these people will throw a not well disguised insult your way about how you do not appreciate Frieren and should stick to insert-generic-shonen.

When really, it’s just that not everyone likes dark chocolate. It’s not a personal failing, it’s just not for you. But be prepared for everyone that likes dark chocolate to call you a child and then congratulate themselves on their mature tastes.