Right. Ultimately, Larian is creating BG3 as a video game and not an RPG. In video games, you save scum, replay a fight until you learn the gimmick of the boss you are fighting.
In an RPG, the DM creates encounters that don't overwhelm and kill PCs but are fun and challenging. It is one of the toughest challenges of a DM, but that's why you use the Challenge Rating system WotC created for you. It is the DMs best friend.
I almost never put PCs in a Challenge Rating of Deadly unless it is meant to be a truly End Game fight, and even then I usually provide them with some sort of way out in case RNG is going poorly. Players in RPGs don't typically like to fail the entire quest they've been working so hard to complete, so I try to be careful not to utterly destroy them.
I actually have an issue with that premise though, as for me that's not good design.
The issue though is the reason for starting the encounter surrounds Laezel and as others mentioned ( I think it was Tuco), it can happen at far too early a level. No if something more nuanced happened here instead of only black and white, get away with it vs get into a nasty fight, then that would/could be interesting. What if the commander took Laezel with him for example, that would at least warrant him flying off and leaving the pathetic grunts to the high and mighty Gith force and give us a choice to make as to whther we want to chase after her, or why not capture all of us and the story goes off on a separate tangent? However if one 80% of the time has to fight, then the game needs to give you more notice.
I lucked out as I did get Astarion up high and cheesed it, but all my other characters died super quickly and it was simply not an encounter that was in anyway rewarding. Now ok, a Dragon slaughtering the guards should be a dead give away I guess, but again Laezel (if in party) is assuring you to approach. IIRC there is no (or little) party suggestion that "this could go south", "maybe we should not all go but have some look for a more favourable position", something to make you the player go hmmm, ok, this reeks of a dangerous encounter. I.e. the game should give you some form of trigger or aid if this is the type of encounter that has little chance of not getting into a horrific fight if you are not prepared for it. To say it's a game you just reload is a cheap copout for me, because it means I needn't bother putting pre-thought with any encounter, but rather rush in, flick through options, die and reload and do it right the next time.
I know it would take away player control, but what if Astarion for example (assuming he was along for this) point blank refused to go near the Githyanki and his pet, he has a talent for survival, so him saying "no, I'm going to take up a position at range" and him auto moving to a given location steathfully might make thematic sense and not leaving a player in a mess. It would make the party members feel more alive and less like sheep.
Again, many of the other encounters give you more of an out, but this one makes little sense and is bloody hard to boot.
