Not Judging, i just see only that you define a BG game just how the first and second one was made in times where such game as Divinity wasnt even possible technical wise. The Core what a BG Game is, is very debatabl ofc. Some say it must follow the first two games to the point and not even considering that technical progress makes it possible to explore new Visual approach. Same goes for trying out new possibilities of gameplay by using the Divinity Engine.
This is Early Access of BG3 and for this Larian gives us the chance to help making the right decisions and find a way to invent Baldurs Gate series anew.
Nothing is written in Stone yet, and staying in the past mostly brings more problems later. That is true for the real world and our lives in this world. Standing still wont do ever in your or others lives.