One of my grad school friends was of the view that we are always in equilibrium and it only seems like we aren't because the model is incomplete.

There's definitely room for lots of different interpretations.

I think of it as the arrangement with no remaining unilateral improvements, which is just a different way of saying what you did.

Undisciplined

econ

Do Markets Ever Reach Equilibrium?

I'm not familiar with these different concepts, but I would have described the concept of equilibrium as the state that the economic system will tend towards, given the incentives involved.  Whether or not it is ever "reached" seems like too imprecise of a statement to even say yes or no to, since the model itself is a simplification of reality 