You'll have to first differentiate between what kind of mesh.
A triangulated mesh in .stl file format is used as an output for 3D printing or for sharing with the community without giving away the IP of the creation process of its geometry.
Scanned meshes can be used to reverse engineered CAD geometry from the mesh. This can require substantial skills and expensive software tools. Fusion 360 has only a very, very limited toolset to do so with the mesh workspace.
The holy grail of meshes is Sub-D or T-Spline control cages/meshes. If done properly those are pure quad meshes and they can be converted into CAD data (NURBS surfaces).
They play an increasingly big role in Industrial Design and Product Design and high-end surfacing software such as Autodesk Alias recently added a Sub-D mesh workflow.
Ultimately, in anything related to CAD and computer graphics, meshes are omnipresent.