I agree that there is a busted factor to it, with Turtonator-GX easily reaching 250 damage. But the fact that it won one recent regional does not mean that it is dominant with no room for other decks, like Shiftry with FOGP in Expanded or ShayToad back in 2015 with Lysandre’s Trump Card. Volc is just like any other deck in that it has good matchups, like Metagross and Golisopod, and bad matchups, like Greninja (which Igor somehow beat) and Gardevoir (even though my Turtonator deck seems to walk through it). I would quit whining about stuff being broken, though. It should not be a term to be taken lightly and the only broken cards throughout history for me were Slowking Neo Genesis and Lysandre’s Trump Card.
Volc's matchup against Gardevoir I would say is 50/50 because it's hard if they get multiple Gardevoirs out. Yeah, you somehow take one out and they have another ready to go. It's tough.