The problem with on-premises sales is that you attract the garage-sale crowd who want to pay $5 for a hard wood dining table. The market is very limited, and casual tire-kickers are 90% of the traffic. Then you have to worry about the thieves who come by to pick off other property from your home when they are not being watched.
At least online you have a national, if not a world-wide market, and opportunities which come with it.
Yes, it is a trying experience in any case. But there is no way any estate will bring full retail value for every item. And every estate sale will end with an employed dumpster even after the “free” tables run their course.