Surfaces are a double edged sword and can feel really unfair in battle, and then really bothersome in post-battle. If you manage to "game it" and pop a fire barrel with some fire and by doing this kill 20+ enemies it feels really cool. But what did you really do? The level designer basically killed the mobs for you. You only shot a fire arrow, that's it.
Some implementations like this is really cool, but DOS-levels of surfaces and chaos is too much. I hear that there are other cool ways to interact with the environment too, like tipping statues, and I like that idea a lot.
Like many others I think that the core spells in d&d already offer a variety of surface effects without the need for a lot of random environmental effects and items.
Larian does such a good job with surfaces I think they can make the spells really shine. This game will be incredible.