As a growing number of baby-boomers look to downsize and declutter their lives, they’re sometimes finding that their prized possessions aren’t as valuable as they thought.

Things that held value for boomers and the Generation X cohort, like family heirlooms and antiques, are a waste of space to a younger set of millennial buyers, a generation known for its minimalism. Millennials, those aged 25 to 35, tend to live in sparse houses or apartments, with as little furniture as possible. They have minimal interest in inheriting or buying other people’s used stuff—and their taste is having a trickle-down effect on older generations.