How Naofumi became a boring protagonist (The Rising of the Shield Hero)

So something I noticed which frustrates me in the isekai genre is when the main characters get a lot of unearned favour from the world they are transported to. MCs tend to come into a world overpowered and that automatically means that all the ladies want him and all the guys are jealous of him and it is so shallow. It's almost like the the story is written by an isolated loser who has no idea how relationships in real life are built and how to earn favour with people.

An example of relationship building done well is Mushoku Tensei: Rudy may be overpowered in the world but that doesn't mean people automatically love and revere him. He has had to fight so hard for his relationships with characters like Eris, Norn, Ruijerd etc. He has had conflict with these characters and it pays off so well when Rudy is able to resolve it and it makes for great developed relationships.

An example of relationships done badly is Sword Art Online where female characters start to fall in love with Kirito just from going adventures with him and not through any growing romantic tension or anything. These relationships just feel so weird and empty.

Now what frustrates me the most from Rising of the Shield Hero is that it had a grasp on good relationship building in season 1. The way the relationship between Naofumi and Raphtalia formed was amazing and is probably my favourite relationship of all anime. The way they had each other's backs while Naofumi was disgraced and Raphtalia was a slave formed a deep loyalty between the two and it felt so earned. Now the rest of his relationships in this season while weren't as well written as his relationship with Raphtalia, were still good. So Filo, Melty and Mirellia felt like legitimate additions to the universe.

After this, Naofumi started being friends with people way too quick and it started feeling like a generic isekai instead of the fresh take it had like it was in season 1. The problem started in Season 2 with the character Ost. When she died, Naofumi's party were really emotional about it like they had a deep bond with her but the friendship didn't feel that deep but I really didn't care that much she died as she was still a new character. Mid way through season 3 and 4, I'm looking at characters like Atla and Shildina and I think, "why are you here?". I can't even remember how he met these characters because that commitment to building loyalty and companionship was completely gone. With Naofumi surrounded with these shallow relationships, he just comes off as generic at the end of the day.

This is only one of many reasons this anime fell off but this particular aspect pains me the most.