>>55260649This is a common misconception that even the anime made, as the series went on it becomes increasingly obvious that Charizard's tail flame is meant to be a literal physical interpretation of its fighting spirit
Spirits are always shown as flames that burn brighter and hotter the more someone is into something, which the pokedex even says is the case with Charizard's tail
Charizard is pretty much your traditional hotblooded anime character looking for a good fight against a worthy opponent, even down to the fact that it lacks any interest in fighting anyone it deems weaker then itself
Pokemon Origin even shows Charizard submerged in water and it didn't effect its flame at all as well
