Historically, what specific trait made mules highly valued over horses for covering vast, desolate distances?

Answer

Their ability to sustain themselves on limited rations.

The economic and logistical advantage of mules historically stemmed from their low maintenance requirements, allowing them to survive long treks where resupply was difficult or impossible.

Historically, what specific trait made mules highly valued over horses for covering vast, desolate distances?
dietanimalComparisonhorsemule