Pension funds still have no mandate to act as ultra high risk VC investors. There are other funds for that.
If you've been sat in high quality government bonds for the last 15 years then you've basically made nothing, or even a loss, in real (inflation adjusted terms).
My pension fund is in 100% global equity. I've got no choice if I want to retire at a sensible age.
'We have a long-term horizon', which in this context can easily translate into 'by the time this blows up everyone responsible will have long left the company / vested their bonuses' is hardly better.
The only good justification for doing high risk investments is 'our investors know, they understand the risks and they want us to do this'.
When you manage hundreds of billions you need to diversify your investments across asset classes and risk profiles. Putting 1% into high risk VC funds makes a lot of sense.