Compared to most crpgs. You have a lot of races, classes, subclass, skills, weapons, armour, spells, other magical items, etc., etc.
Lots of things going on to decide success or failure.
This doesn't mean it'll be hard or easy. But, it is definitely gonna be crunch.
Take FO. A game known for its fun and often challenging turn based combat (well... before you get the power armour lol then it becomes rather easy). It has no more 'crunchy' stuff than BG3 does.
BG2 had less races, classes, and subraces.
My biggest issue with BG3 is respecc since it makes character creation/choices LESS meaningful since it can so easily be changed.
But, yeah, BG3 is definitely in the 'upper tier' of 'crunchy' crpgs. Quality we will see...