According to the Bureau of Labor Statistics, the number of people over 75 years old in the labor force is expected to grow by 96.5% by 2030
https://www.linkedin.com/posts/blackrock_building-savings-through-investing-taking-activity-6965688181828562944-cNhc
About half will do so because they did not save sufficiently for retirement. Others also voluntarily choose to work for social contact, to contribute to society, to mentor others, to grow their skills and more.
