Why engineers are more interested in quasi-equilibrium processes of thermodynamics?

Engineers are interested in quasi-equilibrium processes for two reasons.
First, these are easy to analyze and hence least quantitative information about the behavior of the actual systems of interest can often be developed.
Second, work-producing devices deliver the maximum work, and work-absorbing devices require minimum work when they operate on quasi-equilibrium processes. Therefore, quasi-static processes serve as standards for other processes.