Seems like you did not read the answer already given to you. Yes, you could balance it around for surface effects and away from 5e. But what is the point of making a 5e game, when you balance away from it? The thing that is special about HP/AC/Spellcasting that gets ruined is: the balance. All those things are balanced around each other and versus balanced encounters. 5e has done a pretty good job there and rebalancing it all again would in the end probably mean we get some kind of DOS:2 balance. Which is fine and fun, but distinctly NOT 5e.
You seem to have very little understanding how 5e works, which is fine, but maybe refrain from making those kind of statements then.
At some point you will have to accept that this isn't a TT game. It's a video game where there will be much more combat. Adjusting it so that the combat is more interesting is possibly the most important thing they do. They also have to adjust for a wide variety of competence on the part of the players- this will also require changing some rules.
I understand wanting the game to reflect 5e as much as possible. I want that, as well. But there will be changes, such as giving characters more mobility options to avoid surfaces. Homebrew is a thing, and you may wish to view BG3 as a 5e homebrew. View the game in it's totality rather than critique each and every rule change, otherwise you're just rules lawyering.