Some folk just need someone to cook for them, and not to have to bother with doing shopping, cleaning etc. not everyone in a care home needs medical attention. As the O.P.'s parents are currently at home, they may just be struggling a bit with day to day chores, rather than needing bed baths and...
A gentleman my parents met on a cruise ship, had decided to spend the rest of his days cruising, he was well looked after on board and it was a lower cost than the care homes, I guess this would depend on the level of care required though.