Is studying a waste of time?

If the person playing against the person playing the caro-kann doesn't know how to punish early queen development, then yes most likely his bad opening will steamroll the person because he didn't do anything about it. This both requires knowledge on what to do in a situation when a player deviates mainline theory, and board vision. Not 0% to 100% like you like to argue for. Board Vision just accumulates after you've played over thousands of games. I can remember a game just by playing it over once or twice for a short period, because of my "board vision."

It's not a magical power one brings to the table after years of study either, it's about drilling positions over and over again after they happened to you. If had instead of writing this pointless post and instead drill the correct continuation (given to you by a stronger player after analyzing the game with him/her.) against early queen development when playing against the caro-kann, over and over again, instead of just wasting time yelling at nothing, you would have gained some elo points.

Study is the base of knowledge so just pay attention an slowly but sure you will go up your score keep going.