Revenge stories are better when the death has a purposeful metaphor. Revenge tales need satisfying deaths, either way. Otherwise its just boring. 'Undignified' deaths are usually reserved for cocky, assholish antagonists, not former protagonists. Not to mention the death itself serves no meaning except as a motivation for another character. This is cliched and pure hackery. That death needs to mean something. Randomly getting your head bashed in is a meaningless statement. His death only serves to drive the plot. Its a very lazy device. It'd make far more sense to draw out Joel's death, with Abby taunting Ellie. Abby HAS to be a villain. Otherwise this doesn't work. For example, Ellie is chasing Abby while she's getting messages from Joel over the radio. This cat and mouse game continues until Ellie finds out Joel was dead the entire time and her pursuit was fruitless. The messages were pre-recorded. Abby's point is to rip apart Ellie. To sink her to the depths of absolute despair. This has meaning, because Joel's death reflect's Abby's own loss and agony, and she wanted Ellie to experience it. The false hope of saving someone she loves. To see that absolutely crushing moment on Ellie's face, because her father was sacrificed for her. That is a meaningful death. It reflect's Abby and Ellie's motivations and Joel's importance and the lengths Ellie will go to save him. But Abby wanted to instill a sense of hopelessness and despair in Ellie. It isn't simply about killing Joel. Its about completely breaking Ellie to the depths of Abby's own madness.
That's what revenge is all about. Revenge needs to have meaning and some satisfaction. By doing this, you draw out the emotion within the player, your desperation mimic's Ellie's. You think Joel is alive, so you go in hard. Joel's death is meaningful, because we don't expect it. We expect Abby to just kill him, but her entire point was to inflict the same emotional damage she felt on Ellie. That will then reflect on the player. The endgame is you just picking Abby apart in a fire-fight, but she just laughs and says she never expected to survive. She taunts Ellie to the last moment before Ellie puts a bullet in her head. Maybe Abby herself has a kid, and he's left all alone. Maybe Abby was a terrible parent and neglected him to the point of malnourishment because of her obsession on revenge. Ellie, angry at Abby, but realizing she'd be just like her if she harmed her child. So she takes care of him, because that will complete the circle, and make Joel's sacrifice and influence on Ellie worth something. Because Joel was a stranger, and taught her kindness. She thinks of Joel and their time together, and how he wouldn't want Ellie to leave an innocent child to the wolves, who was mistreated. This shows that their bond goes beyond his death and they're still connected. It makes Joel's death meaningful. Maybe he even recorded his last message to her and hid it from Abby before he died. Due to this, she doesn't become like Abby. She retains her sanity, and meaning in life, and vows to carry Joel's kindness and understand with her for the rest of her life. But that ending would be too 'happy'. Instead we get a sadistic, pointless death just to drive home 'lol nihilism makes me smart, am i rite?'.
Abby needs to be the antagonist here. And there are no ifs, ands or buts about it. She needs to be the main antagonist. She needs to be emotionally deranged and sadistic. She needs to be a completely broken person. Because no one who is hell bent on revenge for years and years and years would have a healthy outlook. It isn't possible. She wouldn't be well adjusted. She'd be unhinged, almost animalistic. She wouldn't be enjoying herself or making sick gains. Someone who is obsessed about revenge for that long will not be psychologically well.
In terms of story, it speaks disrespect to the original source. As a former protagonist, Joel's death should be meaningful. Instead, it negates his sacrifices, trials and tribulations in the first game. Joel dies pathetically. As a writer, you don't want your audience to be pissed at you by having a character they're attached to die in an undignified manner. Undignified deaths are rarely good for protagonists. The only way it really works is to show someone's hubris getting the better of them. A secondary protagonist getting cocky or overconfident and then dying because of his ego in a terrible fashion. This isn't that.
I don't care if its TLOU or otherwise. Respecting your protagonist and the audience's attachment to them are first and foremost. I'm sorry, your friend or whatever is an idiot. Random NPCs or people that aren't protagonists can die undignified deaths if you want to show the cruelty of the apocalypse. Protagonists are supposed to die with purpose. Its incredibly nihilistic and lazy to have a protagonist die in this fashion. And everything about revenge stories are MEANINGFUL deaths, whether it be a protagonist or antagonist. Otherwise they're just boring trash.
Joel is actually no longer a character in the way he dies. He is simply a plot point. There's little to no meaning behind his death. There's no metaphor. He's captured and beaten to death with a golf club, only to serve as Ellie's motivation. Joel isn't actually a real person anymore. His death is meaningless and only serves as a literary device. Which for a protagonist, is fucking terrible.