How much does one need to understand how a car's engine works to drive a car? I believe there is some relevance to a deep understanding of algorithms, that rel

How much does one need to understand how a car's engine works to drive a car? I believe there is some relevance to a deep understanding of algorithms, that relevance being a function of the job. But in situations where the relevance is CLEARLY low for the job, they serve as nothing more than projections of the egos of CS grads, and reduce the value of their company.