Why might certification become a *de facto* entry requirement for competitive jobs even if not strictly required by law?

Answer

Hiring managers see them as evidence of standardized training and professional commitment.

Many certifications, even when not strictly required by law, become the de facto entry requirement because hiring managers view them as evidence of standardized training and professional commitment.

Why might certification become a *de facto* entry requirement for competitive jobs even if not strictly required by law?
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