Less feed is required per pound of meat or liter of milk. Clones also reproduce quicker with reduced complications. This is good for the environment: less fertilizer and diesel is used.
There are issues with genetic tampering of animals and crops. Scientists are saying that despite decades of work no genetically modified crop has yet been adopted worldwide. Because only people from high-income countries eat meat, cloning of cows will not help world hunger.
The real challenge with cloning of cows is the high cost - $15,000 per animal. So meat from them will also be expensive. Genetically modified crops also have the same problem. Thus, cost is the main persisting barrier to acceptance of GM products.