Is circulation real?

No, I don't have any requirement for any type of circulation.
It was Kelvin who defined circulation as the integral of a vector field around a closed path that moves with the fluid. With that in mind, he developed the theory of circulation that
identified a physical law that the circulation of an ideal fluid subject only to conservative forces was conserved over time.
It was the aerodynamicists since Prandtl who have mis-applied Kelvin's principle to a circulation around a path that moved with the wing.
I quote from Prandtl's 1922 paper to NACA where, in Part II , on p 181 with reference to fig 32. (below),

he states :

By drawing the circulation line surrounding the wing, he is clearly using a concept of circulation around the wing. However, by using Kelvin's theorem of conservation of circulation, he is clearly referring to Kelvin's definition of circulation as the integral around a path pinned to the flow.