Older home owners are staying in their homes longer and not selling. This is partially because they are living longer lives and have more wealth than they did in the past. Also because they have extended family living with them and home health care is much better. People are choosing to age in place instead of going to assisted living or downsizing.
The real estate market has been hit with a low level of housing for available purchase since more people are staying in their homes. This is making ir harder for families who are trying to purchase a home while large homes have just 1 or 2 occupants in them.