There is not a linear relationship between technical skill level and "hire-ability". I would describe it as first a step function, i.e. there is a minimum level of technical skill to get an interview and be taken seriously. Then the function is a linear rise, but it quickly levels off to a flat line. Once hired, higher technical skill will correlate with higher job performance and success, but again only up to a point where the curve will flatten out again.

Once you are in the linear portion of the technical skill curve, your hire-ability is much more strongly affected by the "softer skills": verbal & written communication, ability to think critically and express that thought, and the social skills to quickly assess your interviewers and establish a rapport with them.

After you get hired, better technical skill certainly helps, but it does level off. Also, it is not indepedent of the soft skills: I've known individuals with ridiculously impressive technical knowledge and skills, but their utter lack of communication/social skills not only hurt them career-wise, but actually made their high technical skill a liability at times.