This advice is often given on mumsnet and drives me mad. You can not put an adult in a home unless they are assessed as having no capacity to make that decision. It does not matter if you have power of attorney. An adult can decide if they want to go into a home or not. And that includes making decisions that are against their own best interests. They may have a better life in a home and be better cared for, but if they do not want to go, that is their decision.
Similarly family can not just decide the state will pay for a relatives residential home because they think they need to be in one and do not have enough money to pay privately. A care assessment is carried out and a decision made about whether the person needs the level of care given in a home or is fine at home with carers. You can challenge this decision of course. But if your relative is assessed as not needing a care home then the state will not pay for it.
Most people without dementia are at home with carers popping in. If someone needs getting out of bed, washed, dressed, food given and toileting, then carers visiting their home is usually what will be recommended.
Of course many people persuade a reluctant parent to go into a care home. But they still have to agree however reluctantly.