In my own opinion, people are comfortable investing in government controlled investment because it can be trusted and it is legitimate, unlike in crypto space not all projects are legitimate because most bounty projects in cryptocurrency is a fraud and scams, that is why there are only few people who uses and buys bitcoin.
You have already given the answer that the OP needed, people are more comfortable with government/institutional legitimate investments because it is safe. Cryptocurrencies on the other hand has more risks that contains volatility which the other economists coined it "bubble" because of the movement it does and figuratively speaking it is since it is running under decentralized system and the core is just a speculation. People are afraid of what is uncertain, people are afraid of dark passages and people are afraid in losing their money.