Some people honestly think they are sitting on a goldmine of priceless heirlooms. The fact is few people want more stuff. Chipped statues, ragged towels, boxes of photos of unidentifiable people and must old books have very low value today. Even China and fancy silver, too much maintenance for most people.
I remember my friend who was an only child literally carrying most possessions to a dumpster he had put on property. He just did not have time to take off work to clean out the house. A friend and I were literally taking anything we thought might have value to the local goodwill and Salvation Army, in the hope they could keep it out of the landfill.