The OP also overlooks those elderly people who for whatever reason resist care. You can't just waltz in and force them to submit to your probably necessary and well-intentioned ministering. If an elderly person, no matter how at risk, or batshit to the point of violence, is deemed to have capacity, there is fuck all you can do without falling foul of the law yourself.
SS and other professionals won't intervene unless there's a proper crisis and even then you're lucky to get much more than a sticking plaster reaction and a shrug.
It's been a real eye opener dealing with elderly care services over the last year. They will uphold an individuals right to "make unwise decisions", bang on about "the least restrictive options" and the rights of a person even if there's a safeguarding issue and it's impossible to argue with it, because people should retain autonomy and dignity as far as possible. However, things like "fluctuating capacity" can be a useful tool for SWs and Doctors to swerve bigger picture issues.
Last year my SMs mental health went off a cliff - she's 82. Long track record of fragility. Plus organic brain issues likely heralding vascular dementia. She spent a couple of months in hospital being described as "pleasantly confused" as she accused me and my Dad if all manner of awful things. Eventually she was sectioned, and we hoped there would be some progress.
We hoped in vain. A particularly arrogant psychiatrist lifted the section and sent her home to frail 85 year old Dad who'd been her carer for 14 years since the last episode to work on their marital differences despite documented antipathy and aggressionfrom her towards him. Within a week she'd physically attacked him three times and he had to leave for both their safety, rendering him homeless as she owns the house outright.
She continues to live there, allowed to harrass my Dad on a whim in between insisting on no contact, who still loves her and frets about her, while having her confidentiality and autonomy preserved by the CMHT. If I wrote down everything that has happened in the last 10 months you'd accuse me of being a fantasist. But trust me, I did have better things to do than go into battle with medics and the authorities for shits and giggles. Not any more apparently.
Trying to care for elderly resistant relatives who don't want you to is a battle many people face, and often "services" are obstructive and unfit for purpose.
There are thousands of me out there, you can identify us by the ten thousand yard stares and the unhealthy coping mechanisms. And no, I don't have siblings, and no, there are no other relatives. And no, I can't just "switch off" or walk away. Money means absolutely nothing to me, other than bus fare backwards and forward to the hospital which is my life for the next month, at least, and after that who knows?
So forgive the rant and ramble, but "cosy intergenerational living" is going round and round in my head and making me feel a bit manic.