I wont Debate the specifics of your father’s situation since I don’t know them, but if he has some home equity, a car that’s paid for, and some income, he’s not doomed with destitution. Apparently his partner had much bigger income that afforded your dad a nicer lifestyle than he can afford on his own income.
We have that scenario in my household. DH has SS income of around $25,000. I have income of $56,000. When I die, my income stream disappears. When I go to the nursing home, my income will cover about half-the cost and I will pull half from first, my assets, then from our joint assets.
Fortunately, DH has healthy assets in his name only, and then our joint assets are healthy. And then, he has his family farm that he can sell! Only by then there will be so many owners tangled up in it, it will be impossible to sell. But that is completely his problem.