I asked DDG if a magistrate judge was a minor judge:
“Yes, a magistrate judge typically holds a lower-level position with limited authority compared to higher-level judges, handling minor legal matters such as traffic violations and small claims cases. Their powers are more constrained, focusing on specific types of cases and administrative duties.”
loio.com Ballotpedia
US Magistrates hear portions of all types of cases, even the most important.
You’re conflating a municipal magistrate with a federal one.
Your city magistrate deals with matters no deeper than speeding tickets. In federal court, magistrate judges are appointed to assist district court judges in the performance of their duties. Magistrates oversee first appearances of criminal defendants, set bail, and conduct other administrative duties.