To your final point I will again say that this is not a table top RPG, it's not a pen and paper RPG, it's a computer RPG, a video game, it's going to take time to kill enemies, you aren't just rolling a dice and the outcome is set, that's random luck, not skill and almost all gamers want skill involved so no, we don't need a 'kill-all-enemies button'. As I said at the beginning, you are just going to have to accept that the genre has evolved along with the technology and you're going to get a very different experience than you got with BG2. However the game will most likely ship with difficulty levels and like DOS2 (and other games) have a story mode where fights are so easy they're over much faster.
I am going to disagree heavily with this point saying that it should not be like the PnP D&D cause it reads like you think PnP stuff is always solved with a single dice roll, which is inaccurate. Often times there are passive checks if the DM chooses the use it which just takes your stats in account and passes and fails on that. Even then though, RNG is a big part of 5e. Normal 5e has no kill all enemies button, and combat is a mix of skill and RNG. You have to account for positioning, what affects what, resistances, whether you might hit your allies with a spell, and many other strategical elements. Dice does come in play often though to resolve many attacks and skill checks to add an element of randomness, as if you succeed every single time you open your mouth it is boring in PnP, and it can be boring in a videogame. Because there isn't really much aiming other than for AoEs, you need a system to make it that people can miss, hence the RNG, AC, and Saving Throw Systems. The RNG is not replacing skill, but is filling in for where skill can not function, as without it you would have your instakill button because you would just click and never miss. In fact, many of the DOS elements that have been added have both hurt RNG and Skill elements of D&D because you don't have to strategize as all you need is a barrel and the highground, or a ledge and a mage hand. Combat is over instantly, with nearly no RNG or Skill implemented. BG3 has an instakill all enemies button right now, and so the intended difficulty is gone. Yes the Genre and Technology has evolved, but so has Pen and Paper, and the game systems behind it are tight and can easily work in a computer game. In fact, as much as people hate hearing about it, many bring up that Solasta has done the exact thing of translating pen and paper 5e to a computer game and the gameplay is considered the best part of the experience. BG3 is considered better in cinematics and presentation right now as far as I know. Additionally, saying the genre has evolved doesn't actually help cause yes there are many QoL improvements, but many core things have stayed the same and many things are still quality years later, hence why many many many games still use RNG (even games that have deviated from the Genre like fallout has an RNG system with VATS), Isometric is still considered the ideal view for a game like this, and abilities having limitations like cooldowns or needing a resource like a slot. Heck, you see many parts of the industry returning to older style games like with Pillars of Eternity harkoning back to how BG1 and 2 played. Heck, many of the older series known for their RNG are still staples of the genres they are part of like Fire Emblem, XCOM, Final Fantasy, and even Fallout (with how much it has changed). Being older doesn't make the systems bad, and in fact I don't have the nostalgia associated with BG1 and 2 cause I sadly missed them when I was younger and instead started playing them within the past few years and found them very engrossing with the game systems, party, and combat. Yes we are going to get a vastly different experience from BG1 and 2, but I don't think it is because systems have improved so much as we have changed from AD&D2 to 5e and BG3 has a much more modern presentation, but at the core there is still much that should be the same.
Ultimately, I think this game genuinely would become a much better game by becoming closer to the D&D rulesset. I am not saying chuck ever bit of homebrew that makes the game better, there are changes I like, but I am saying move toward a ruleset that has been proven to work with the game and start the deviations from there, and I think you will find that the game will actually become far more skillbased than you think.