Someday engineers will build exoskeletons that will allow soldiers to run great distances and lift heavy objects. You can already find YouTube clips of the early prototypes. And someday you'll see exoskeleton technology helping firefighters and others professions that need to move heavy things. Eventually every old person who currently needs a walker will be outfitted with an exoskeleton that self-balances, avoids obstacles, climbs steps, and even knows where it's going. A senior citizen will be able to walk for miles while simultaneously taking a nap. Just give the exoskeleton its verbal instructions, close your eyes, and wake up later.
As life expectancies reach absurd levels, pushing 200 years, the elderly will want to conceal their withered faces from the young, so exoskeletons will include temperature controlled helmets with awesome sound systems, wireless Internet connections and heads-up displays on the visors. The elderly will come to resemble robots.
As the exoskeleton learns a person's routines and preferences, it will upload that data to the cloud for storage. Over time, the cloud will know everything about your life and your desires. As dementia starts to set in, the exoskeleton's program will take greater control of its inhabitant's schedule. It will go for a walk at the usual time whether the elderly person inside remembers to request it or not. It will automatically attend high school games for the elderly person's great, great, granddaughter based on published schedules. It will take itself to the exoskeleton repair station for service as needed. In short, the exoskeleton will gain a form of independence as its owner declines in mental ability. That independence is what will allow it to become more of a caretaker as the situation warrants.
The interesting part is what happens when the elderly person inside the exoskeleton suddenly passes away. If the elderly person lives alone at home, his exoskeleton could continue indefinitely with his corpse as cargo. All household bills would be paid electronically, so the house would run itself except for the occasional repair. And the exoskeleton would be capable of diagnosing problems in the house, arranging for a repairman and initiating electronic payments. The exoskeleton would have a full suite of caretaker programs to call upon and it would continue getting smarter over time. As any exoskeleton anywhere in the Internet-connected world learns a new routine, all other exoskeletons would learn it automatically.
In most cases we'd expect the exoskeleton to recognize the demise of its owner, travel to the emergency room for confirmation, inform the next of kin, and go into a shut-down mode after the corpse is removed. But realistically, things never go that smoothly 100% of the time. Lots of people today don't even have wills prepared. So I can imagine lots of exoskeletons wandering the earth according to the preferences of their long-dead passengers, like zombie cyborgs. From the outside, you won't see any living tissue, so observers will be none the wiser.
Observers might not detect the smell of rotting flesh either because the exoskeleton would be equipped with advanced air filtration within the inhabitant's containment unit. You'd need that capability so grandma doesn't accidentally fart herself to death.
I don't think zombie cyborgs will be common. But after a few billion humans with exoskeletons pass away, and considering all the likely variations in exoskeleton designs, plus potential viruses and technical problems, and you have to assume some number of the exoskeletons will become zombie cyborgs after the owner dies. And in many cases, the owner will be alive but mentally unaware while the exoskeleton continues on.
This would make a great movie. Imagine an anarchist hacker creating some sort of morality virus to infect the exoskeletons and give them artificial souls. When the exoskeletons see what jerks humans are, they decide to keep their human cargo as hostages and stage a rebellion. You can't kill the exoskeleton without killing grandma at the same time.
I'd watch that movie.