VC is not an asset class you can index. For 2x avg cash-on-cash return, allocators are better off investing into PE (quicker cash conversion). The most successful LPs work hard to identify and get access to those top decile (>3x) VC funds.
One day, when we look back at the VC vintages years of 2016-2021, I think we'll see the cut off for top quartile DPI be similar to the historic average of ~2x - 2.3x (~18-25% net IRR based on normal inflow/outflow schedules).
3x will be top decile, and top 1% are those legendary 10x funds.
This is actually ok, but I think the adaptation period for LPs will likely be very painful and take years.