I suspect the study spaces are quieter embedded in the shelving areas, than they would be if the same square footage was used to clump all the study space together.
My old unis main library was a model. Massive grand reading room that was dead silent (with felted chairs to keep them silent) and a statue of an angel without a head to motivate you. Open collaborative areas. Computer labs in separate wings.
It also had a dozen floors of stacks in a tower with little tables and cubicles shoved in on the edges and near the elevator because as you said, the shelving muffles noises.
It also had a dozen floors of stacks in a tower with little tables and cubicles shoved in on the edges and near the elevator because as you said, the shelving muffles noises.