There should be a service that people can sign up for that would have someone call, text, or email to check in on people with no family or friends. That way if something does happen to them, and they do not respond to repeated attempts at checking in, authorities can be notified sooner than 4 days later.
And I bet someone smarter than myself could figure out a way to have the service subsidized so it is not expensive for people to use; especially older folks who may be on a fixed income.