Will the cabinet significantly reduce noise from switches, fans or other equipment?

Not significantly.

The doors and panels may slightly soften some direct equipment noise, but these are ventilated data cabinets, not acoustic enclosures. Air has to enter and leave through openings in the cabinet, and sound is unfortunately quite capable of using many of the same routes.

If a switch sounds like a small aircraft preparing for take-off on the workbench, putting a glass door in front of it isn’t going to turn it into a library appliance.

For noise-sensitive installations, choose quiet equipment first rather than relying on the cabinet to silence noisy equipment afterwards.