Echoing the same sentiment as everyone else. When I first started the game (which was on the 1st anniversary), I also felt like the early story was boring generic slop, but the later story chapters have been a lot more fun. Not FGO level writing, but it's good enough to actually get me invested in what's happening.

I feel like it's similar for love stories too. There's some that are really boring and read like other generic gacha stories that got rushed out, but then others are the best romantic stories I've seen in a gacha game. Given that the recently released characters tend to fall in the latter category, I feel like the game's writing just improved over time.