Condo buildings and homes also have application process and rental office (aka the realtor's office). Are you saying that real estate agents who advertise on those websites but a commission payment will be required (even if the house is owned by them)? Not that it matters, the agent pay the commission from one hand to another?
Finally, you agree that some real estate agents who may work for free because they are hopeful that when a person comes to purchase they will call them.