Remember that anime characters have more restricted card pool. They're restricted by what the duel planner in the production team gave them.
That's why burn cards in anime doesn't seem to be as OP as in real life. The cards that would make them OP as a deck are not there. When you apply real life deck building to them though, then you'll realize there are combinations that can make them OP.
But that's supposed to be the main appeal of Volcanics. Going into the offensive, disrupting board, and if your opponent turtles, you punish him with burn damage. Nerfing that aspect of theirs is stiffling their very design.