I agree, lots of wasted potential. One thing that really bugged me was the lack of character interaction/focus. A lot of the characters appear briefly for a chapter or so and then peace out, apparently preferring to chill out than getting involved in the main storyline. Like… Mordecai, Brick and Tina really felt as if they should have had a bigger role, especially considering Borderlands 2 and how they seemed close to Lilith.
Maya’s death is very sudden (and kind of stupid) and you don’t have enough time to get to know her as a character to make it feel impactful. Like people have said, Bloodwing and Roland’s deaths in the previous game were way more emotional. It also seemed to have a bigger impact on the other characters. All the vault hunters were hit by the deaths in Borderlands 2, and Tina even had a dlc about her dealing with it. Here, there’s just a few lines of dialogue and then they say it’s a war and carry on. Zer0 doesn’t seem torn up, Axton, Salvador, Gaige and Krieg are all absent, and it’s just kinda… a waste.
Rhys doesn’t do anything once Katagawa’s dealt with, and there’s only throwaway lines referencing tftbl rather than any explanation about what happened.
The Calypso twins are pretty boring. They could have done some interesting stuff, maybe with Troy realising he can take powers from other Sirens and deciding he doesn’t need his sister anymore, and then their conflict. You could have the whole ‘the enemy of my enemy is my friend’ and briefly team up with Tireen as a necessary evil to defeat Troy before she inevitably backstabs you. Or, you could have them having a more emotional bond with one another, so when Troy dies she seems more upset and her fight with the vault hunters feels more vengeful and motivated because you killed her brother (rather than not seeming to care at all).
Honestly the gameplay is solid, but the writing in this game could do with a lot of work… I’m really hoping they get some new writers onboard for dlc, or a sequel.