Uncle 90, bad vision, bad hearing, recent stroke, barely ambulatory. Wife 84, increasing dementia, functions normally about 50% of the time. They live in a house with no equity, neither drives, she can't cook, 3 daughters in area who rarely visit, son 3000 miles away, basically have no savings, takes both of them to make a phone call. They have minimal monthly income. I am also concerned about them being scammed buy any number of different methods. I live 2000 miles away, but can occasionally visit.
They both refuse to consider moving into assisted living. Other than leaving them alone until one (or both) suffer a major injury or illness, or other calamity, what avenues are available to me to get them into a care facility?
You might try calling the agency on aging in their state for suggestions. Also you could ask the adult protection services to check on their welfare.
Have they been active in a church? Calling their pastor might result in advice from a person they respect. Sometimes outsiders have more influence than family! The same might be true for a doctor.
You are a kind and thoughtful person to want to help these people when their own children don't seem to be doing it. (Although they may have tired with no success. I'm not judging them without more information.)