The Arithmetic
The rate gap is enormous. The term gap is the catch.
Unsecured debt in Canada is expensive. Credit cards commonly sit near 20% to 23%, store cards close to 30%, and unsecured lines of credit well above prime. Secured mortgage money costs a fraction of that. Moving balances from the first column into the second reduces your monthly obligation immediately and often dramatically.
The catch is amortization. A credit card balance you would have cleared in three painful years becomes a mortgage balance repaid over twenty-five comfortable ones. At a much lower rate, over a much longer period, you can still end up paying more total interest than you would have if you had simply attacked the cards.
That does not make consolidation wrong — for most people it is clearly right. It means consolidation needs a plan attached: keep the payment at or near what you were paying before, apply the difference as a prepayment, and do not let the cards refill. I will not put a consolidation together without walking you through that part.