I can't imagine the time invested in doing that. If you really want to dedicate that much time and energy be my guest. If you don't use it on the goblins they just use it on you.

As far as I can see though it's just another level of tactical involvement. It makes you pay more attention to the details around you instead of "there's my target, CHARGE!" instead of having as many traps that you can't see until you're right on top of, most of the hazards are out in the open. I'll take that any day. Especially when I can weaponize them myself.

I've seen several comments about how long these barrels/ground effects last and even if they're a 35gal barrel instead of 55, oil isn't going to burn off very quickly and a full round where everyone has taken a turn in DnD represents 6 seconds realtime. If they're that much of an obstacle carry water jugs or the create water spell to clear them. Ray of frost is great for cutting a path through fire. Combined with fire bolt you can really clear your path through most things. And should all those fail you jump it.