To a significant degree, the need for credentials in the first place is a real-world acknowledgment that people, left to their own devices, may not be trustworthy about their own accomplishments and depth of knowledge. Thus there needs to be an outside arbiter, a yardstick to apply, to demonstrate convincingly an attainment of knowledge and skill through being put to the test in some way, either academically or through a skill assessment evaluating some kind of athletic ability or things like fine motor control, creativity, memory retention, and so on. Such credentials might vary widely in their value and applicability and often become a kind of crutch in and of themselves where people can bandy about their degrees when often the degree itself might now be far removed from what the individual is expected to have in their skillset and knowledge base.
After all, learning is a lifelong process for people in any kind of demanding arena. The training and education leading to an academic degree, for example, begins to be outdated from the moment of graduation onward, and in fact, much of what is studied and learned in school, even at the graduate level, will be lagging behind the broader world in most fields of endeavor. So when people are evaluated as prospective candidates for employment, for example, or are to be given access to organizations and have a potential degree of influence as a collaborator or consultant, it is most convenient to check such credentials as are available as a point of reassurance and kind of real-world test, that they at least meet perhaps minimum criteria, knowing all the while, people are inherently unpredictable and may well be dishonest in exaggerating their capabilities to promote themselves as best they can to exaggerate and make claims of prowess and accomplishment that are biased towards the positive.
So we would say that the need for and reliance on such credentials is very much a product of the dysfunction in the physical realm, that such things are needed. In a sense, most education is make-work and a test of the ability of people to essentially follow instructions and become compliant when being directed by a kind of slave master making them jump a series of higher and higher hurdles, whether they like it or not, whether it is truly engaging them in a meaningful way in something they want to learn and value, or whether it is simply a mandated requirement that they absorb the knowledge and regurgitate it at test time. This is because most of education has little practical value and is designed to be a kind of prison and a containment to keep humans out of real life and having a positive impact as long as possible and to, in effect, ill-prepare them for being productive, happy citizens.