If we start using dynamically linked libraries on Linux and macOS that’s potentially a big project. That involves changes to both the library and Blender build systems, and not just USD because it also depends on other libraries. Another thing is ABI compatibility with binary add-ons, graphics/compute drivers and the VFX platform, where we currently rely on symbol hiding on Linux and macOS.
This may be worth it, however getting the Python bindings working with static linking can also be considered.