Ghosts of Saltmarsh has brown mold, green slime, collapsible floors, slick floors...pretty much all in the 1st level adventure
The first two are types of monstrous traps/dungeon hazard (green slimes have blindsight, ffs...) Collapsible floors are a traditional trap, not a surface, and slick floors are a form of difficult terrain.
Surely you recognize that there's a huge difference between spontaneously igniting Grease for a 30 foot fire blast and a thoughtfully designed 5x5 foot single-target trap without special elemental interactions.
