I disagree to an extent. I think environmental mechanics absolutely has a place in 5e, just not to the extent of DOS2.
Not really arguing it should be "removed". It just needs to follow the rules! Here's a great example : https://www.dndbeyond.com/spells/create-bonfire
This cantrip creates magical
fire with the following effects:
1. Affects 5 foot square. That's the size one medium (human) person occupies on the map in tabletop. So it hits one person.
2. It does 1D8 damage and you get a save to take zero damage
3. You do not take damage walking through it. I repeat you do not take damage walking through it
4. You take damage if you stand in it on purpose by ending your turn in it. With a save for zero damage
They're this strict even with magical fire. Also here's another really important point: https://www.dndbeyond.com/spells/grease
In previous versions of the game you could set grease on fire. They specifically removed this ON PURPOSE because it was too strong in 5E.