@bythewell - I think it can be difficult for some people to admit that they need help, or even acknowledge that they need it.
But vomiting is a very good example of how something can go seriously wrong. Even a younger person who gets food poisoning and doesn't have help, can get into serious trouble. An older person in the same boat doesn't have the same reserves to drawn upon and if they are at home alone they might end up dead.
I don't think older people all need to go into homes, but I do think that past a certain age people who live alone need to wear one of those medic alert bracelets that monitors health and alerts the ambulance if the person wearing it needs help.
If you've got a bug and you're weak from vomiting you might not be able to seek help after a certain point. You should do what you can to make sure that scenario doesn't happen.