. I don't think BGs had that much of systemic simulation. It relied mostly on hand crafted scenarios when compared for Fallouts which used systems when creating problems to solve
Yep. But the ideal is to having everything(lore, artstyle, combat, exploration and dialogs in line), i hate for eg, when warlocks are teleporting, conjuring hordes from nine hells and doing all cool stuff on nwn2 OC during dialogs, dungeons and cutscenes only to when join in your party lose the ability to teleport(which is on P&P), to control multiple summons can't grapple enemies with chilling tentacles. Or when a cleric can revive the dead, but only the dead which died in combat. the dead who died on cutscenes can't be brought back to life. BG1/2 is not perfect, but is far better than other games. Eg : Slayer form on BG2 can impact your party relations and when you have to deal with mindflayers, the temptation to use the slayer form is huge trade off.
Other old school games did the ability to use supernatural stuff off combat better. You can use domination on dialogs on vtmb, can use disciplines to help you with hacking, or lockpicking, or even to help on stealth, your social skills are very important, even on combat since ammo is expensive as hell, and highly social skills makes purchasing expensive ammo cheaper. Mainly .50 AE for DE and flamethrower fuel. BG is not bad in that aspect. On Arcanum, if you are a necromancer, you can even talk to the dead to get information and solve the quests in a alternative route. On Gothic 2, people threat you differently if you are a Fire Magician of Innos or if you are a Mercenary for eg.
Pathfinder Kingmaker also did a amazing job. You can depending the quests decisions and kingdom management decisions, have even alterations on the final chapter, if you researched some stuff or not. Or even if your capital will have undead workers which construct things quicker than normal workers but a lot of people hate it or not. If you have golems protecting your capital. Depending on your alignment, your buildings are different. Lawful guys can't construct brothels. Evil guys can solve the quest involving lizardfolk in a different way. IF you play as a Wizard, the scrolls which merchants on your city can sell you are tied to your realm's arcane rank. so you invest a lot of arcane buildings and researches if you plan to play as a wizard. And so on. Hell, even a unique adviser exists depending on your alignment.
Chapter 4 spoilers bellow. A lich. The lich who attacked Varnhold can serve you if you are evil and pass some dialog checks. He is a good advisor and solving some troubles with him is far easier. You can also traffic the soul jars that he collected for monetary gain.
And i can only judge BG3 by the gameplay videos. But seem amazing how dialog checks seems to be able to affect your relation to party members. I really wish that BG3 will be a amazing ROLE PLAYING game. And have impactful decisions.