Sechel, writing a lot does not make one bigger or smaller. There were minor poskim who wrote long volumes of teshuvos, and there was the bais halevi, who wrote relatively few teshuvos, yet his words are חוצבים להבות אש. Rav nossom adler, one of the gedolei olam and the chasam sofers rebbe, wrote nothing. Most of the geonim wrote nothing too.
Sometimes writing longer seforim is evident of the opposite of gadlus.
So I’m not impressed with “kamus,” im concerned with eichus.
And i can’t believe someone here said that rav miller wasn’t a gadol… He was one of the biggest bekiim in shas in his time