While its true that the cards that recieve nerf suggestions on a regular basis do not need a nerf or change as urgently as expressed by frustrated players and overall the game is fairly well balanced you cannot say it is perfectly balanced. A meta cannot be established in perfect balance...there has to be something "better to beat". In this case this is clearly valkprof.
It isnt really toxic but since we all seem to have realized this, it might be okay to tweak one of the stronger cards of the deck down and maybe buff another card here or there to open a door for a meta change. Which is fun. And fun keeps people playing and paying. Digital CCG have this HUGE advantage that they can change things on the fly if needed, so why shouldnt they?