The big problem is that there is not 'signalling' on the cargo side.
On the pax side I know of cases where on day (1) competitor dropped prices on a group of destinations. Unfortunately this included one very important city for my pax-colleagues. (think 2 daily for 'us' and 2-weekly for 'them'). On day (2) my pax colleagues dropped prices on every single city where competitor operated 2 or more daily and we operated a lot less than that. on day (3) competitor worked out the message and put the price for 1 city back up again. on day (3) plus a couple of hours all 'our' prices went back up again.
So no 'conversations' all totally open and transparent via all the magic systems that the pax side for getting prices out into the market. So no-one in jail
Now try to think how to do that in real-time on the cargo side. I've tried when a big competitor introduced a service to a city very, very important (think stupidly profitable) to us. His rates were less than 50% of ours. Plane stupid. My answer was to drop all our prices into his 'home' market from all points under my control to less than 50% of his. Result big complaint at very very high level (think at Board-to-Board). Luckily I had run a quick brief all the way up the system. So the response from our side was along the lines of "we cannot discuss pricing in this way, but perhaps you might like to consider what our man in "Xcity" is trying to tell you"
A week later they worked it out and their rates went up to just a teensy bit below ours. everyone happy and making loadsamoney.
But mostly it is impossible to signal in the cargo side