Why was the huey helicopter known as the workhorse in Vietnam?

Prior to the invention of war machines, horses (plus mules, oxen, elephants, dogs, etc.) pulled the guns (artillery), pulled the wagons, carried the men, etc. those animals that could do it all were called "workhorses" (at least the horses were). Helicopters in Vietnam did it all...fired rockets, fired gatling guns (called mini-guns), fired machineguns, rescued downed jet pilots, searched for downed airmen, picked up wounded men, picked up dead men, dropped off men everywhere; battle or general operations. Choppers even carried supplies, building material, tractors, boats, everything in Vietnam. Out of all those birds the UH-1 Iroquois (Huey) carried the most, the most times. Everything but what it could NOT carry such as heavy guns, tanks, or downed large aircraft. The UH-1 was rugged, produced in mass numbers, easy to maintain, was fast & reliable, and made a good gunship, medivac, and troop insertion aircraft. The Huey (minus what was mentioned above) could do it all...it was the workhorse of the Viet War.