As someone who has played TTRPGs for over 20 years, many of which spent with D&D, I can confidently say that playing BG3 has very little to do with the experience of playing D&D. BG3 is still a video game with all the limitations and pre-made choices (dialog-wise, in terms of mechanics, world Interactions etc) as any other video game. I would compare what's going on in my head while playing D&D to reading a book and visualizing what's on the page in my imagination.