A mortgage (literally a "dead pledge") dies as a contract when it is paid off or repayment fails. I don't have a mortgage any more. We took ours out in 1981. In those days you had a proper interview with a Battleaxe Mk.1 from the Building Society. She scrutinised salary details very closely. She could (and did, to others) say "No". We went through interest rates as high as 17% at one stage. We never missed a payment.
We are obviously returning to those days but in the meantime we have thousands who are financing mortgages that they can't afford in houses that aren't worth anything like what they paid for them.
Who's to blame? The ones who borrowed the money or the ones who were prepared to lend amounts that were clearly unsustainable. I'm just glad it isn't me.