Who's even using agents at this point? Youd be better off taking a less than ideal offer than the commision they charge.
You can't advertise on domain or RE unless you're an agent.
Seems like a hole in the market
They used to, there must be a compelling reason why both major players gave up on private listings.
Money and data. They charge around $600 for a listing, but agents also have to (typically) link their CRM, and they tend to give them high-quality data compared to private sellers.