This is a few weeks old, but I felt it is relevant here. Noticeably absent from the "speculation" as to the reasons fewer people in their 50's are working is the elephant in the room: Ageism. I gave up searching for work because it's painfully obvious my capability is not the issue. AARP has permanent support education for 50+ people trying to get hired.
All I hear about with respect to frustrations being unable to find a job is focused on the youngest, while it's the eldest that are being forced out at alarming rates. The worst part is we don't have any recovery path, and some of us are supporting adult children who can't find work.
We either navigated all the pratfalls life throws at us and have savings enough to "survive", or we didn't, and we become another near invisible member of the predominantly elder population of homeless standing by intersections hoping for a handout.
Next January possibly millions of over 50 people thrown out of work and unable to find any job (even minimum wage jobs) will lose their health coverage, since Medicaid begins requiring 20 hours per week of work to qualify.
We are well beyond "fearing dystopia" now. We've been living it for a decade, some would say longer.
The world run by MBAs...
If you are old in a professional field, you have years of experience they have to pay you for, so they hire the young guy to make the payroll smaller, even if it causes problems for some other department, because no one high enough to do anything about it is going to catch it.
If you are in the general labour space, making min wage, they know they can't expect the same energy, and can expect you to know the 'advancement' they dangle over ambitious min wage workers' heads doesn't actually exist, so they will get more labour out of a kid for the same money.