Mag drives last forever if maintained correctly.
However, lack of maintenance can cause some organic sludge buildup in the impeller area which could be causing some unwanted humming or noise.
However, if the pump was running in low water level and sucking in air for an extended time. You could've either damaged the magnetic impeller or cracked the ceramic shaft holding the impeller. Which would cause quite a ruckus.
My suggestion is to take it apart. Inspect it for damaged or worn out impeller and shaft. If everything looks good. Give it a good cleaning and possible do a vinegar bath on it. If it's just dirty. That will clean it up and have it running semi silent again.
S8