The cost of transparent recruitment process

Transparency in organizations has tremendous benefits. But it doesn't come for free. Let's take recruitment process as an example.

If there are only 2 autonomous decision makers, then the process is simple. They screen CV, meet the candidate, have conversation, check the tasks that the candidate was assigned, may have a quick follow-up to and that's it. Usually this is enough to make the decision. Feedback can be given to candidate even immediately if recruiters are experienced.  In case of 1 decision maker it is even simpler, but it's usually good to have at least one more opinion.

But what if we would like to make that process transparent? Score the candidates by measuring them somehow to show where the decision comes from? It may be easy to measure A/B/C test score, financial expectations and years of experience, but not everything is so quantitative. Measuring personality, value of the experience for the company, attitude, personal growth potential or some creative task may be tricky. It may require to create complicated recruitment process and metrics to justify the final decision transparently.

What are your opinions? Is it worth to invest in transparency in this case? Or it's better to trust the decision makers and just have informal notes about the candidates? Have you ever wondered what should be the proper balance?