I have thought about the Mirrer Yeshiva in NY and Shar Yashuv in Far Rockaway and realized that it is highly  unlikely I would have come to any understanding of Torah without hearing classes from the great roshei yeshiva in these two places.[Rav Shmuel Berenbaum and Naphtali Yeager] since I can see the same thing when I learn Physics. There is only so much I can get by reading. Without hearing from an expert is like trying to learn how to play the violin from a textbook.

And in the Middle Ages this was also understood--that for any discipline, whether shoe making, or painting or boat making, one needed to learn from an expert.

So what was the question of the Gra about the creation of a "yeshiva" as a seperate institution from the rav of a city? I can imagine the issue was that he saw the future abuse that this would cause. Still, one way or the other it is clear that Rav Chaim of Voloshin decided that it is important --even if we do not know if the Gra agreed or not. [There are two versions of the story.]