This doesn't make sense. Why are you comparing people on a cruise to people who need round the clock medical grade care?
There is a huge difference between a Retirement Village and a Care Home. A Retirement Village (or sheltered accommodation) is where older people live independent lives, in their own flats, within an elderly community, that has tailored facilities for them, like entertainment venues, restaurants, gyms and nice gardens and communal areas for people to get together. My dad lives in one of these. He bought half the flat for £155k, and he rents the other half, which costs him £723 a month.
A care home is where people end up when their health has deteriorated so dramatically, that neither they or their families can provide adequate care for them (think, incontinent, immobile, dementia etc). These cost around £7000 per month.
Your friends pay £7800 a month (£3900pp) to live on a cruise ship. Now granted, that's cheaper than if they went in to a Care Home, which would cost £14k a month for both of them, BUT, it's significantly more expensive than if they had stayed in their original home, or moved to a Retirement Village.
And no one would move themselves into a Care Home if they were still healthy enough to go on cruises. Would they??🙄