I do not feel sorry for the elderly person sitting on a large and expensive property who demands to spend their final decades squatting on land which could house a family and allow parents to get to work within a reasonable amount of time. They have options the young person does not. They can get a reverse mortgage, for example. They get social security, and draw down on whatever pensions and investments they've accrued over their lives. Their costs are much lower - they don't have children to support. Or they can move, and I'm sorry, but it's not impossible for a retired person to move. Millions of them do it every year all over the country. Often to really nice elderly communities full of activities and specialised care.
I say all of this as someone who leans more libertarian than collectivist. Society is interconnected and interdependent. We cannot function if he keep young people under our boots. Asking the elderly to move is a *very* small price to pay if we expect the young to shoulder the enormous tax and debt burdens said elderly have imposed upon them.