I don't really think so. First of all, you have dedicated cargo movers, like Cargojet, as well as the big airlines moving in belly space. Most of the air cargo is moved by the couriers: UPS, FedEx, Lynx and Purolator, and of course Cargojet.
Cargo moves pretty well, then. The big airlines are now into this. WestJet and Air Canada both have cargo services now, so they're operating that as well. I don't hear anybody ever complaining about air cargo.