But when it comes to (I don't have a good term..) unique objects, like houses, or shares in a company, they exist and have an owner. A court can simply declare "you don't own that house any more, this person does". A business doesn't become ownerless forevermore because someone lost a private key.
With houses it's not always that simple. Often in real estate fraud cases an 'agent' will sell one person's house to another and skip town with the money. If the courts revert the deed to the original owner then the innocent buyers are still out all that money.
If the money is in a bank account in a foreign country, a court may have no jurisdiction to recover the money.