Older people suffer from fear of, or actual experience of, feeling incompetent, not important any more, or unloved. We might fall into defensive modes when threatened with these experiences, which probably postpones finding solutions to the dilemma.
Creativity to the rescue! Finding a situation or person for whom you can take an important role, and exhibit competency is a real possibility. Several of my friends have taken on an ESL student whom they see once a week for an hour. Even love can develop between mentor and student when a freely given gift of speaking one’s own language makes another person thrive.
There are always going to be others that will need what we have to offer. All it takes is a little creative thinking, and a search on the internet until you find your target. My aunt Carolyn used to drive around the “old” people to their doctor’s appointments. She was in her eighties but felt young, useful and important taking around the ninety somethings.