I haven't gotten to the DoS series, so the use of surfaces I am enjoying. It adds a tactical layer to the game that is much needed, since it adds some level of immersion and realism to it. Like why would w wizard want a fire bolt that doesn't set things on fire?
Because the way it's set up now makes firebolt stupidly OP? In 5e the firebolt cantrip should deal 1d10 fire damage and not set the person on fire, meaning the max damage you can deal with a single firebolt is 10. In BG3 right now, it does 1d6 fire damage, sets the enemy on fire which does 1d4 fire damage, and it applies that right away and then a second time at the start of the burning enemies turn, as well as when they move out of the fire surface that was created underneath them. So, assuming I luck out and get max damage rolls on all of that, that would be 6+4+4+4=18 points of damage from a starting cantrip. That's a chance at getting a 1st level spell worth of damage out of a cantrip that can be used as many times as you want without resting. Not to mention, even if you miss the firebolt altogether, it will still do damage. Not even kidding, I've killed enemies with a firebolt that got a "critical miss" meaning I should have missed them so badly that it would be embarrassing, and instead it just exploded in their face for no direct damage, but still set them on fire and dealt 3 damage. Then, when it swapped to their turn, they took another 2 damage, and then when they went to move out of the fire surface it created under them, they took even more damage which killed them. And I missed the attack. It's just not fun and completely broken to have a cantrip that I can spam as much as I want without penalty be able to kill enemies that I miss attack rolls on, when by all means they should have laughed in my face for missing my attack and proceeded to smack my wizard upside the head. As for it be "realistic" how is setting a floor made of stone on fire? Last I checked, stones don't exactly burn well. Setting a wooden object on fire should be possible obviously, but just being able to spam a line of fire across the stone floor to force enemies that have to get close to me to literally walk through fire to reach me is just plain stupid.
