Everyone now owns wherever they are living. Current owner residents get reimbursed via taxes for their current equity over a period of time. People and government win, corporations take losses on investments and probably come out ahead anyway.
Obviously an oversimplified idea, but I think we should be asking “How can we make this happen?” more often than dismissing outright.
What I’m proposing you wouldn’t lose the 300k because you still have your house and you’ll get the 300k back over time. And yes taxes don’t come out of thin air, but the whole system needs plenty of overhauling.