A dispute between a landlord and a tenant could quite easily result in a easy profit for the agent, and here is a possible scenario:
You are renting a apartment priced at 30,000 RMB each month and you have already paid a security deposit of 60,000 RMB to the landlord, now 6 months into the 12 month contract you have some problems with the plumbing, electrics or other issue with the apartment.
You then contact the agent who then claims to contact the landlord on your behalf and then tells you that the landlord is being very unreasonable, possibly even threatening.
You are now left with the few options of either to put up with the defect or whatever the dispute might be for the remainder of your contract and hope to get some of your deposit back, or cut your losses and find a new apartment.
Meanwhile your agent might appear to be doing all they can to fight your cause with the landlord, however they could simply be negotiating with the landlord for a % of the security deposit you would lose for breaking the lease contract early.
When you finally decide to cut your losses and find a new apartment, if you use the same agent. “and in some cases your company might have a signed sole agency agreement” that agent will be set to make a tidy profit on the next apartment you rent.
They also now have the apartment you left available to lease to another unsuspecting client.