A thought experiment; mandatory age of retirement at 50 vs. UBI

75% of the under-50 workforce is serving lattes and trying to pay off student loans. Mom and dad spend their retirement savings in Florida, can’t support adult children.

Your thought experiment is a kinder version of Logan’s Run.

This gets rid of workers, especially experienced workers.

Other countries won't do likewise. This gives them an advantage. They pull way ahead in economic power.

Because goods and services are traded across borders, the more-restricted economy sinks quickly. To put it another way, if your share of the work is smaller, your share of the benefits will be smaller.

> mandatory age of retirement

This makes so little sense that I have no idea why it's in the question at all and why it's compared to UBI.