Chickens you eat for meat aren't raised in little cages. I guarantee I am the only one on Zoochat who has ever been inside a poultry house or involved in production agriculture.
"Free range" is a marketing term for inner city people who have never seen a chicken.
Your guarantee is a little wrong, as I am a full time farmer.
You are right though about meat chickens not being kept in cages. All caged chooks are for eggs, as it makes egg collection much easier. Free range layers are much more labour intensive.
Meat chooks are a special breed and are so big and heavy that they only walk short distances at a time. They are kept in large barns with many feeders and drinkers. They spend most of there time sitting while they eat or drink and only stand for short periods. I know people who have bought meat chooks to breed with their chooks to increase their meat yield. They behave exactly the same in free range situations and even though they have acres to explore, they just move between the feed and water. They dont live long either and the oldest I know of is 2.