You folks really would've burned Baldur's Gate 1 and 2 to the ground if this little mix-up to the numbers game is bothering you.
At any rate, if you find yourself only battling from high positions, that is largely due to your play style, as the game provides plenty of opportunities for you to take the fight to the enemy on the ground. There are 3 fights that come to mind where height advantage is more pronounced, maybe 4 with the Phase Spiders depending on how the AI teleports, but I find this introduces as many ways to creatively resolve problems as it does advantages. For example, if you destroy the elevated surface an enemy is on, they're likely to take a pronounced amount of falling damage, or even die. If an enemy AI is flocking to a surface because of height advantage, even if it isn't destructible, you can apply an Area of Effect spell or surface to it that punishes them for their trouble, or lay makeshift traps in the form of barrels.
Ambient surface hazards are another issue altogether, since other posters mentioned them in passing. There's a distinct overabundance of them to the point of dependency in the level design. Dungeon traps should be things hidden in unique ways, not an explosive in the center of a flammable toxic fog.
At any rate, I don't know how you all play D&D, but battle mechanics are secondary to telling a good tale and allowing for a good amount of roleplay, I'm excited for more content and I'm really enjoying the game so far. Cheers.