Comment by lenerdenator

They're beneficial to younger generations, provided that there's enough value generated by the younger generations to cover the cost of the pension.

The problem is, this new wave of retirees - the Baby Boomers - did not have enough children. Their children's generation - the Millennials - can thus charge more for their labor. The Millennials also aren't having enough children.

This means that the people generating the value are taking more of the value for themselves to live on (though not relative to inflation, but that's a different conversation), and there's fewer of them contributing to pensions through various government revenue schemes.

Also, anecdotally, my parents have far more expensive plans for their retirement than my grandparents ever did.