Thank you for the info !!The Cornish X meat chicken is a multi-line hybrid developed over decades to produce the most possible meat in the shortest possible time with the greatest possible feed conversion efficiency.
Any chicken can be raised and eaten for meat, but some turn feed into meat more effectively than others and no animal in the history of the earth has ever done that better than the modern Cornish X.
There are other common meat birds, noteably the assorted "Rangers" or "Colored Broilers", which have been bred with more emphasis on suitability to pastured conditions. They take longer and consume more feed in reaching the same butchering weight, but some prefer them because they suit either their philosophy of chicken keeping or their management system better than the Cornish X do.