Can we not give fault to the engine? I doubt that most of the people here (myself included) actually know what's possible or impossible with it. Saying "the engine can't do it" just absolves Larian of responsibility and fault. Many of the things mentioned here might actually be possible with the engine!
-e.g., Day/night cycles: change the lighting (definitely possible) and possibly NPC cycles (almost assuredly possible) after a certain amount of conversations, time spent exploring, short rests taken, or one of many different criteria. Bam, day/night cycle.

Also, Larian/WotC chose to use this engine to make BG3, so they're still ultimately at fault even for the things the engine can't do. The question then becomes, are the benefits of this engine worth the lost potential features?