Something worth noting with shared dependencies is that yes, they save on disk space, but they also save on memory. A 200MB non-shared dependency will take up 600MB across three apps, but a 200MB shared dependency can be loaded on it's own and save 400 megabytes. (Most operating systems manage this at the physical page level, by mapping multiple instances of a shared library to the same physical memory pages.)

400 megabytes of memory usage is probably worth more than 400 megabytes of storage. It may not be a make-or break thing on it's own, but it's one of the reasons Linux can run on lower-end devices.