There are definitely similarities if you zoom out far enough. The object shader (task shader in Vulkan) basically maps to the tess control shader / hull shader,

There are definitely similarities if you zoom out far enough. The object shader (task shader in Vulkan) basically maps to the tess control shader / hull shader, and the mesh shader maps to the tess eval / domain shader. One big difference is that tessellation is fixed function and doesn't allow you to control the topology / primitive connectivity within each patch. Another big difference is that the mesh shader runs as a workgroup, which allows things like parallel geometry decompression where all threads of a mesh shader workgroup collaborate in the decompression.