I think many pension aged people would be willing to work part time if there were flexible jobs available. Normally in our last 10 years of working, we are at the max allowable vacation scale, and many of us have more discretionary income; for going away on vacation, spending January in the sun, taking a few weeks to visit family when they need us. We don't want to give up the flexibility we have earned.
Case in point my brother, who is a long distance bus driver. His typical day was start at 6, did a 3 hour run and turn around, to be home by dinner. Covid put a stop to that run, which typically was geared to tourists. His only other option with his company is charters, which often means overnighting in a hotel. He doesn't want that job, so has taken a leave and is looking for something else. He would gladly work part time, but most trucking/bus jobs call for 10 hour days. He is late 50's and wants to work less, not more. He is contemplating early retirement. Such a shame when there is a shortage of drivers everywhere.
My DH had the same issue. Phased out of his job in early 50's, but all offers at his skill level were looking for young blood, and did not offer any flexibility. He took his buy-out and retired early.
I hear very many similar stories. So many in health care retiring early because they cannot do 12 hour shifts. Perhaps try 6 hour shifts? Unfortunately, management seems to be a bit blind and not think outside the box at times.