The Dyson Supersonic is a premium hair dryer used frequently in daily grooming routines, so reliability is tied to airflow and heat management. Common issues often trace to airflow restriction (clogged filter causing overheating), cord/strain relief wear, or internal electronics that manage the motor and temperature sensors.
If the dryer shuts off intermittently, overheats, or loses power, check maintenance and filter cleaning first; many "failures" are preventable. Repair can make sense when the problem is a replaceable cord, filter housing, or a known internal module, particularly if the unit is within a reasonable age window.
Replacement is usually better if the motor control electronics fail out of warranty and the repair quote is high, or if there are repeated thermal shutdowns despite proper maintenance. Because this is a high-cost item, comparing to the threshold is especially useful.