One thing I never really got about BL3 was what the writers' vision was for the Youtube Twins. It seemed like they were trying to recapture the magic of Handsome Jack... but, for whatever reason, it never really clicked. Some of the elements were there, but either they weren't put together correctly, or they'd be done already so it just made you miss the stuff Handsome Jack did.
I think part of the problem was that the Youtube Twins didn't really seem like a credible threat; they were a good concept for a stage boss, but not the Main Badguy.
Jack was this sociopathic gigachad that you couldn't help loving to hate. He was cooler than you, richer than you, handsomer than you; he was the Hero of the game, a Hero who murdered people in cold blood and threw tantrums like a spoiled California child, and he was going to stomp you out like Big Tech stomping out freedom of speech. It was almost like the writers of BL2 were deliberately making Jack into a Mary Sue (a trope everybody hates), so that he'd be easier to dislike. Everybody hates a winner, and Handsome Jack goes a step further by giving you legitimate reasons to hate that winner.
But the Youtube Twins? I dunno. They were "popular kids", too - Tiktok stars, Twitch streamers, Millennials who put "social influencer" down on their resume. That could be a funny and annoying gimmick too, sure. But the Twins never really seemed like gigachads. They never seemed "authentically cool", like some Hollywood superstar, or the bodybuilder who shows up at the beach and kicks sand in your face - someone that YOU hate, but you also know that NPCs and idiots love. No, instead, the Twins were like Jake and Logan Paul - goofy jobbers. Yeah, they're popular, sort of, but they're popular for all the wrong reasons. People think they're numbskulls; you tune in to their videos to laugh at how clueless they are.
iirc, the BL3 suicide mission had Handsomette Black insulting you too ("gunslut", I think she calls you?), but it doesn't feel as personal and biting as Jack's humiliations. Just kinda feels like, I dunno, a casual findom session with a sassy chick who's trying her best, but - eh? And then there was the death of Maya, which was CLEARLY meant to recapture the drama of Jack killing Roland. That didn't really work either, though, because one, I saw it coming from a mile away, two, Emo Onision is even less threatening than his sister and had nowhere near the credibility Jack did by that point in the story, and three, even if I didn't see it coming, my first reaction was oh yeah, I remember Roland's death. Man, that was sad! Borderlands 2 was such a good game. Wish they'd make a villain like Handsome Jack again! It's supposed to be this grand climactic moment where you get super invested in the plot and, choking back your tears, swear revenge against those FUCKING FUCKERS RRAAAGGGHHH - but instead it winds up being a little interlude to reflect bitterly on how much you miss Handsome Jack. And I don't think it's just me, either! Because if you look at the normal fan reaction, almost everyone who goes through that scene walks away hating AVA, not Handsomette and Onision. How are you going to have this pivotal Bad Buy showdown scene, where you sacrifice one of the better characters in your storyline for the sake of putting the villains over, only instead of getting your audience to hate the villains, you unite your audience in hatred against the plucky young Coming of Age Heroine that you've been desperately building up as the next Main Hero / Face Character for the entire franchise?!?
And again, I'm not anti-Ava by any means. I actually really liked Ava; I appreciated her hustle, and I was hoping they'd make her a playable Vault Hunter in the future (not much hope of that NOW, I think). But I can't deny that the BL3 writers fucked up their villains so bad, that it was easier to hate the main heroine than it was to hate the actual villains.
Also, another thing that pissed me off (no, really, I liked BL3! It's a good game) was the way the Youtube Twins' storyline just... dissipated. I actually thought they were building up to some cool shit, like all these little hints were being dropped about how Onision, the runty bitch of the pair, was starting to come into his own, flexing his muscles and building up this seething incel resentment towards Tyrean. I fully expected the two of them to turn on each other at some point - like, maybe right at the end of a pivotal boss fight, Onision stabs his sister in the back and steals all HER energy, then he flies away and now you gotta go fight some sororicidal tranny Triple-Siren. Maybe before she dies, there's a mini-redemption arc, where Tyrean does something nice to help you? Or maybe before HE dies, Onision has a mini-redemption arc where he regrets what he did to his sister, and there's some touching flashbacks to when they were just innocent little kids, looking to get off their planet? The stuff with their dad and their childhood diaries was actually really fun and (could have been) genuinely emotional, but I was also expecting some kind of twist or drama WITH THE TWINS, RIGHT NOW CURRENTLY. Instead it just wound up being, oh, you beat the boss, I guess Onision's dead now? Oh, you beat Tyrean, guess she's dead now too? Oh look, here's Lilith to save the day now I guess, even though she's dead. Yaaaay, you don't matter...?
tl;dr BL3's villains were a failed attempt to do Handsome Jack again.