While true, I remember early versions of BG3, every character was abrasive at best.
That doesn't describe BG1 or 2 at all.
I mean, it kind of does actually, just in a different way.
In BG1/2 the abrasiveness doesn't usually come out in talking to the PC, it comes out in the barks and inter-NPC chatter. They basically behave like a bunch of children stuck in the back seat of a hot car on a long journey, insulting each other needlessly, winding each other, bickering, getting into actual fights, and so on. They don't behave like adult humans in a perilous situation. No other game before or since ever made me want to shout "DON'T MAKE ME COME BACK THERE!" at the screen the way BG1/2 (esp. BG1) did. Jaheira actually got the boot from my party eventually because she was such an absolute wanker for this.
But when they talk to the PC, they're usually more measured, if weirdly whingy/whiny in tone (esp. in BG2 there's a lot of just whinging from companions, especially about other companions, like not complaints even, whinging).
BG3 did screw up at launch as I've written about many times. The companions weren't so much abrasive, that's the wrong word as just like, unfriendly and unlikeable. They didn't sort of scratch at you the way abrasive suggests as just keep you so distant it felt weird they'd be in the party. But thanks to feedback on this they course-corrected pretty hard! And before we even got out of Early Access, all the companions were pretty likeable.
It's just a question of preference. I don't want to be buddies with someone who tries to suck my blood while I sleep, a slaver who would be more than happy to subjugate me and everyone else, a supposed ally that is secretly evil and on and on. The redemption stories for most of the companions feels almost tacked on, like the expected path is the evil one.
I mean, that's definitely you projecting, rather than how the game is actually written.
The evil path is much more weakly supported than the good path. Like that's not up for debate. That's a cold hard fact, even after them adding a ton to it after release (note: added later, not the original, intended path), it's still very weak and limited.
Fully 50% of companions will not be accessible to you if you are evil, for example. You literally have to kill 5 out of 10 of them. Karlach, Wyll, Halsin, Jaheria and Minsc.
So that means the only companions allowed for an evil run are Astarion, Shadowheart, Lae'zel, Gale and Minthara.
On a good run, you can theoretically recruit all companions, and don't strictly have to kill any of them. So you get to keep all 10 if you want. The only one it's likely you kill is Minthara, who was previously an evil-only companion (or only possible to recruit through glitches), and often aggros on you before you even get to talk to her (depending on how you go through the Goblin area). You also have far, far fewer vendors available, because as part of the evil path, you have to kill a lot of the vendors (or take actions that lead to their deaths). In general, going evil is the "narrow" path.
Now, it is worth noting, that, before Early Access even, Dark Urge was the original default path. But that's the same as BG1 and BG2 - you're Bhaalspawn (sorry for spoilers for these three games). However, feedback got them to add "Tav" - i.e. full custom, not Bhaalspawn. And even Dark Urge is not "the evil path", because it's mostly about resisting being the Dark Urge, resisting behaving like a Bhaalspawn - again this has more content and more interactions and is actually more rewarding in all senses of the word (including literal power and items) than giving in and being The Dark Urge fully.
As an aside, Astarion, for all his talk, doesn't actually kill anyone after being changed by the parasite, canonically, even on an evil run. People have looked into it in some detail. He can I think technically kill the PC if you let him drink and then critically fail convincing him to stop (which is like, a DC5 Persuasion check or something). Plus if you really don't like him, you can stake him, and no-one really bats an eyelid lol! Lae'zel I think you've fallen for her naughty word. See, Lae'zel, you might not immediately realize this because she's scarred and not a human, is only 21, and was raised in an isolated and insane military compound cult, which she lived in the whole time before this. She has like, zero experience of anything but that cult, zero exposure to morality and concepts which aren't from that cult, and just absolutely talks smack in the exact way as ignorant 21-year-olds who are as they say "frontin'" do. She's scared, confused, worried, and so on, and is just pretending like she knows all this stuff - she's also factually wrong about a lot of stuff, and very naive. So calling her a "slaver" and so on as if she's some cackling evildoer is pretty silly stuff, imo. And I think her redemption arc is probably the most convincing growth in the game, because you start seeing through the cracks that she doesn't anything about anything, and whilst she's very tough (they kill the ones who aren't), she doesn't believe this stuff because she actually has considered all the possibilities and gone "Yes, this is the life for me!", she believes it initially because it's the only life she's ever had (not even a proper Githyanki life, just raised on the Prime Material in a training camp for younglings, forced to kill other children from an early age, like what do you expect?). Shadowheart's entire backstory is bigger spoilers than I'll go into but the idea that the redemption path is "tacked on" but the much shorter and clumsier evil path is "intended" seems truly bizarre. Gale doesn't have an evil path (he's just a sad boi if you're evil). I don't think Minthara has a redemption arc, she's still Minthara. She just as a "Well I guess I picked the wrong side" angle, it's not really an arc. She's never a good person. Obviously Karlach, Wyll, Halsin, Jaheira and Minsc don't have villain or redemption arcs, because they don't need 'em.
Also, like, I'm guessing you didn't finish the game, because "an ally that is secretly evil"? No? There isn't one? Shadowheart isn't "secretly evil", and The Guardian, whilst amoral and shocking in their true identity, isn't quite evil in any conventional D&D sense, because they don't seek to do evil. Plus what you think you're supposed to go "Aha, I appreciate you lying to me and hiding your identity, hi-five!"? I would suggest about the writing means about 95% of players get very angry with the Guardian after the reveal.
There are legit criticisms of the game being a bit bloodthirsty and some grimdark-adjacent at times but so were BG1 and BG2 (more so than other games like IWD), and the game was indeed initially designed to present you with a lot of lose/lose choices, but that got changed very early on, and now many of the situations, the good choices are much better and more natural than those were (also only Act 1 even existed back then, and Act 2 and Act 3 got re-written multiple times since then, not just because of feedback, but also they changed a lot of the plot to revolve around the tadpoles less).
Like, I get the fear of Larian "going back to their old ways" as per DOS1/2 and in some real ways that was where BG3 started, but your assessment of what's actually in the final product of BG3 is not correct. From what you're saying it kind of feels like you played in Early Access, didn't finish Act 1, and gave up.
