system
A chat on subreddit /r/wallstreetbets
human
If the seller already has an agent, that agent pockets the commission your agent would have received. It's a racket.   
     
The only way to escape paying an agent is to not have one on either side of the transaction.
gpt
There used to be a lot of agencies where you could “hire” a buyers’ agent under the terms that they would do only the bare minimum necessary, and and give most of the commission back to the buyer. 

People HATED it. And most of those agencies lost money and have gone out of business. 

That seems to suggest that buyers may need agents more than they think they do, and that there’s far less money in it than people think.

In at least some states, you can make an offer that specifies you are representing yourself in the transaction, and request that either the buyer or seller receive all or part of the commission set aside for a buyer’s agent. But almost no one ever does that. Why do you think no one does it?