If landlords can't pay mortgages, they and the tenants will lose the properties when they're repossessed
But they won't, as they can only be sold to people with the sitting tenant who can't be evicted, so they'll be sold to professional landlords getting a good deal, at some point they might lose the property, but then you're argument is that throwing them out sooner is in some way a good thing?
The landlord chose to run a business with significant risk, when risk hits, they lose the capital, that's to be expected, losing capital isn't a massive deal.