I never understood what's the advantage of buying shares in a trust over buying the underlying commodity itself.
Well i'm just a private individual not a VC though.
I'm also just a private individual. That's why I don't have a massive, impenetrable vault in my basement for storing my gold, instead I just buy gold ETFs. Similarly, although I have the technical experience to safely store my bitcoins, most people do not. These people will certainly not buy actual bitcoins, but they may be willing to invest in a bitcoin ETF where they don't have to worry about that. That's the advantage.
However this advantage comes with the added risk of not directly controlling the commodity and having to trust the ETF entity so I doubt it is a true advantage.
Neither gold or bitcoins need much storage space. And in case you own considerable amounts you can also afford extra security.