They have many counter: blizt, heavy hitter like hidan2, stronger over time like roshi & jonin minato, heavy burst like wind empress.
The only reason they've been so meta is because player always make the same mistake as of AP said. Yes it is true that you can lose to them just because of 1 mistake but as long as you can execute your plan perfectly there's nothing they can do. Immortal team are very VERY limited tactic wise, they are not versitile unlike burst or blitz.