It's worth noting that the larger companies mentioned like Uber, Slack, and Twitter which received money from the Vision Fund occurred in their later respective funding rounds, often shortly before going into an IPO or full-on acquisition by a publicly traded company. My guess would be that this fund is targeting modest returns while not wanting to incur the both the risk associated with a company in its earlier funding rounds, and a guaranteed path towards liquidity if the fund managers desire to exit. I see this purely as an investment vehicle since investments at these stages aren't expected to provide the investors with significant numbers of voting shares.