Actually all wealth can be considered illusionary. A share bought today could be worth significantly less tomorrow because of the release of some bad news. Same with a business you own it could be going fine but then there are change in circumstances such as a competitor opening up next door which takes allot of your business away and as such devalues your business substantially. Property is no different - it may be borrowed money (same can be done for other asset classes) but at the end of the day it is the borrower that is responsible to meet the obligations. The bank is not a shareholder they are just a lender - if they were a shareholder there would be no loan and the bank would share both the liabilities and the profits/losses.
