Pacing/ plot design, for instance, or the whole "evil path" and interpretation of evil in general. Although I'm not saying it needs to be thrown out, because it's too late for that, but if we're noticing it, it's fair to say it needs work. I would be satisfied with good enough at this point, although obviously it's a shame to keep lowering standards for big budget projects.
Pacing I agree with -- it's strange that the plot tells us that our heads are going to explode in 7 days but the camp dynamics are designed for 10+ days of activities. But the evil path? What would you differently?
The complaint I've heard most often is that the evil path is bad because is evil is stupid -- but that's just the Forgotten Realms. The realms are setting where heroes defeat evil and, contra Darth Helmet, evil loses because evil is stupid. In this setting, people do stupid things because they fail to see hook hiding in the bait or the bait is just so tasty that one forgets about the hook.
Selling your soul to a devil = stupid. You will spend eternity in hell.
Worshiping an evil diety = stupid. You will spend eternity having your vitality sucked out by a demon-spider-goddess.
Joining an evil organization = stupid. Name an evil organization that hasn't been burned to ground in the last 100 years or so.
BG 1 & 2, killing people as lamprey faced monster = stupid. Do that often enough and your soul will be destroyed when Papa Bhaal uses you as fuel for his rebirth.
In the realms evil is always a path to self destruction, the question really becomes "why do some travel that path"? And the answer in BG3 is a lust for power. The tadpole, the Absolute will give you power that the druids can't offer.
I'm interested to hear if you have a novel critique but I suspect that the fact you aren't a fan of the BG series becomes a problem.