It's a puzzle to you because you had the personality & motivation to do the work of marketing+showing+negotiating the house yourself. You have inadvertently projected your DIY savvy onto other homeowners to do the same thing. But, a lot of home sellers don't want to DIY a home listing.
- some homeowners don't want to deal directly with potential buyers (pre-qualify buyer's bank financials, show them around the property, etc). Some homeowners are uncomfortable wearing a "salesmen" hat.
- some homeowners are not savvy about how to present and market their home. Sure there are endless books and youtube videos on jazzing up "curb appeal" but some people simply want a "professional" to advise them.
- some homeowners feel uncomfortable with legal aspects and even hiring an attorney specializing in real estate feels "weird". It's just more "normal and easier" to use a real estate agent.
Analogous situation in people selling things on ebay. What's the value in a service like iSoldIt[1] charging a commission for ebaying on sellers behalf when the seller can save money by DIY by taking own photos, using ebay website to upload the photos and list the item, and then pack & ship the item themselves?!? The value is that some people don't want to DIY certain tasks. I had a friend sell his camera via iSoldIt. I sell stuff myself on ebay all the time and thought he was crazy for paying the iSoldIt commission. He was a young programmer so he's not an old grandfather that would find ebay's website intimidating. He simply didn't want to deal with the whole ebay workflow and wanted some cash as quickly as possible. Consider that ebaying a camera is way simpler than selling a house and yet some still offload it to a service to handle it for them.
EDIT to replies:
>, but I don't think most people would be willing to spend 12k just to be more comfortable,
>Agents provide value. [...] Do agents provide tens of thousands of dollars of value?
To be clear, I wasn't trying to justify their 6% commission rate. I was explaining why most homeowners don't go the DIY route to save money which seemed more "logical" to the gp.
For decades, I saw endless commercials on tv for FSBO (For Sale Buy Owner) services trying to educate viewers on "don't pay seller commissions and pocket the thousands in savings yourself!" And yet, real estate agents persist. People are already aware of "selling by owner"; they just don't want to do it and would rather pay a commission.