I just checked your post history, and it seems one of your projects still relies on having somebody help filter out bad actors. I don't think it is that different from how escrow works in a marketplace. If you plan to solve the necessity of an escrow then you need to build a tool that is smart enough, easy to understand for everyone, and not prone to false alarms so that it can solve any issues from both sides. I'm not sure if removing human intervention is the only solution since contexts do matter and a code might not be able to handle it. CMIIW.
Yes the marketplace operator would help filter out bad actors from even being able to list in the first place and being an arbitrator should disputes arise. A robust feedback system would be used to filter out bad actors. Users of the marketplace are incentivized to keep excellent feedback reports for their account if they want to keep using the marketplace and deal with other highly rated users.