If we want to replace c-mount lenses by s-mount lenses it begs the question …
Can s-mount Lenses replace c-mount lenses in general?
Of course lenses should be of similar quality …
Can s-mount Lenses be as good as c-mount Lenses?
To answer this question, we should define what’s “good”. At least we should get an idea about …
How to improve Lenses …
In general we can assume that objectives are optimized in a way. Why is that so? Let’s assume an objective has, say, 6 lens elements. We can assume that all of these lens elements are needed, to achieve the quality of the lens. Not needed, the manufacturer would sure work with fewer elements, as this would increase his earnings. Maybe there is a better design (from a better designer) with fewer lens elements, but we can assume that the original designer did the best he can …
How to improve the lens then? Improving a lens implies to change the directions the light beams travel. If there’s no need to change the directions, there’s no need to change the lens at all;)
Light travels straight (in optical homogeneous media) and changes directions only at the interface between air and glass or at the interface between two types of glass.
To change lights directions additional lens elements will be needed (for the assumed optimized lens). More glass means higher cost and a larger footprint of the lens (let alone a redesign of all other lenses in the system … you in general can’t just change ONE lens element but have to work holistic. A new lens element or a reshaped lens element influences all other lenses in the system.
As production costs are limited by constraints of the target price and the mechanics, there definitely are limits for the s-mount lenses and markets that will be c-mount markets for a long time or forever.
A general replacement is c-mount by s-mount is not possible for the same reasoning, however in my personal opinion 50% or more of the c-mount lenses can be replaced by s-mount lenses.
For the pros and cons of c-mount and s-mount lenses please also check …
Comparison: c-mount lenses vs. s-mount lenses (M12x0.5)