A lot of people in the US only have a 401k which is their pension for this discussion (there are very important differences, but for this discussion we can ignore them). In their 401k an index fund is almost always your best investment, so you should be concerned with anything that makes an index fund a worse investment since it harms you.
Pensions have strong and weird investment rules, and you have no control over what they do other than law. This makes them generally a worse investment (but if you live longer than average they are great anyway) so a 401k is better for most.
Pensions have strong and weird investment rules, and you have no control over what they do other than law. This makes them generally a worse investment (but if you live longer than average they are great anyway) so a 401k is better for most.