zzzz - I have no idea why it isn't popular to discuss other ways of doing things. I listen to what the community care solicitors/barristers and independent social workers say is likely to happen.
I don't care what goes on in other parts of the world. They have different family set ups, child care systems, etc and its not relevant to us, here in the UK. (And yes, I worked on a helpline for parents of disabled children, and we got calls from all over the world, because ours was the only number they could find relevant to them, so they told us what things were like for them)
My empathy is for mothers or fathers in this country, struggling to cope with an adult with say SLD, challenging behaviour and severe medical problems on their own. Women can regularly be subjected to violent attacks by their adult child. My DD does not have challenging behaviour, but she is stronger and two inches taller than me - she can push me over; or slap us really hard anywhere, when we are not expecting it.
Given how cash strapped LAs are, social care is IMO in a worse state than the SEN system. Parents are only going to get specialist residential care for their adult disabled child, if even SS recognises they can't cope - and that's about as easy as getting an expensive independent specialist school placement in the SEN system.
In my own case, not only can we not cope with DD1 - and even the social worker considers that her needs are beyond any family; but she and DD2 cannot live in the same house. DD1 is in tears all the time about the fact DD2 is "normal", can go to university, go out drinking, etc. DD2 is suffering grief over the loss of her sister - because DD1's epilepsy is progressive. The prognosis for DD1 is moderate-severe cognitive degeneration (already happened), severe behavioural problems and psychosis. DD2 has developed a host of mental health problems, and been taken to A & E 5 times this year for being suicidal. The social worker considers DD1 just needs to be somewhere safe (ie specialist epilepsy placement), and DD2's needs are greater - because she needs our support. Mental health services are not looking after her.
We have Sophie's Choice. If we have DD1 to live with us, we will have to sacrifice DD2 - the one, who can get a first, get married, have children and hopefully look out for DD1, when we are gone.