This is something I witnessed with my mom when she retired at 70 last year. She is no good at sitting still with idle time. Even though she was able to retire from her full-time school nursing job, she still decided to work after retirement. Now she just works a three-day work week, but still goes into school to be a nurse for young children. I think she likes having purpose and helping the kids, even though she doesn't HAVE TO anymore.
I've spent far too much time working as an independent contractor without a 401K to think I have a reasonable shot at a comfortable retirement. Instead, I'm pulling for AI and subsequently, some UBI to help humanity once the need for labor subsides.
Runs in the family, eh?
I think we should all have possibilities to do this, especially since people are far healthier at 70+ than they were earlier. My day worked in some capacity all the way up to 80 - the last years it was donating his time as an art teacher to community groups.
You are also taking the investment route, so without a retirement fund, you still have a decent chance of being okay too.
Oh yes, oh yes, oh yes... I come from a long line of people who can't sit still!