Have any previous DnD video games stuck completely to the rules? I'm not aware of any. I'm not sure how many DnD TT player groups stick to the rules either.
Strawman argument. There are many other changes to the 5e rules Larian has made which don't have people complaining about them, like Speak with Animals lasting until next long rest or until losing concentration. I don't think anyone is complaining about the special weapon attacks Larian has made as well. It is clearly not the case that people are complaining merely because BG 3 is not being a precise exact duplicate of the 5e rules.
You are completely ignoring the detailed discussion about exactly why these specific rule changes affect the balance. Do you have any defense for why 56+ sources of advantage/disadvantage with a cost or drawback should be thrown out the window for free advantage with no cost from backstab and height?
Why is this 56 number propped up like it's some talisman of defense to change the game as it is?