Yeah, small chickens are hard to find. It used to be that. . .
broiler/fryers were the small chickens, 2-3.5 pounds, and that is just about all one could find many years ago. The chickens did not grow so fast as now and if they got too much bigger they were tough or if tender, they cost more (Roasting chicken).
Just recently a local supermarket had a special on for whole chickens for $.69/lb. I bought the limit of three and they were all 3.5 lbs or smaller. This is unusual for our area as most sale chickens are in the 4.5 to 6 lb range (!). When I got married 25 years ago, a six pound bird was a roaster, and commanded a higher price. Now birds in the 4.5 to 6# range are the norm.
I think that not only do the chickens grow bigger faster but all the small chickens are purchased by the fried chicken chains. I know they have to make a buck, but I really love Popeye's spicy fried chicken, but the dang pieces look like cornish game hen pieces!