A garbage disposal is a rugged appliance, but failures typically come from jams, seal leaks, or motor electrical issues rather than "wearing out" in a neat way. Common problems include leaking seals, worn impellers/grind ring components, mounting flange leaks, and motor capacitor or overload failure after repeated hard jams.
Repair can be worthwhile if the issue is a simple jam removal, reset/overload problem, or a mounting/plumbing leak under the threshold-especially if the motor still runs smoothly. Replacement is often better when the unit hums but won't spin, leaks from the body, or has persistent grinding noises, because internal seal or motor problems are rarely economical to rebuild on value-tier models.
If the disposal is older and corrosion is visible, replacement reduces the risk of sudden leaks under the sink. Preventive habits-cold water flushing and avoiding fibrous scraps-meaningfully extend life.