Like ∇^2 u = Δu = f? It's not really cryptic, it's taught in multivariable. And it's not done to look sophisticated, it's so that you can instantly recognize that it's Laplace, or Poisson, etc.

If I tell you B = (dA_z/dy - dA_y/dz)i + (dA_x/dz - dA_z/dx)j + (dA_y/dx - dA_x/dy)k do you instantly see what operator is applied? That's why you just write B = ∇×A.

People presenting ideas in shorter notation is not showing a lack of progress - usually it's the opposite. In old optimization papers people would write out the entire normal equations, entry by entry. Not really insightful at all, compared to A'Ax = A'b.