As a founder I've raised through crowdfunding multiple times. The experience is great on both the startup and the investor side, and I love that crowdfunding lets more startups get off the ground, especially ones that don't have access to SV money.
But this should really be thought of as "gambling" instead of "investing." There's very little ability to do due diligence and the companies are usually so early that it's impossible to know if it's going to work or not. However, if you have money you're willing to lose it's a lot more rewarding than spending it at the blackjack table.
This is a good take, and underappreciated - but there's a larger point being missed.
In high-social-trust situations, there are fewer benefits to blockchains. In low-social-trust situations, people aren't a good option. Bockchains provide an entirely new and welcome option for that scenario.
Relatedly, there are different kinds of distrust: mistakes and attacks are one, but platform risk is another that blockchains can alleviate. Putting it another way: I trust Twitter/YouTube/PayPal to generally work without issues, but I don't trust them not to change their offering in an exploitative way or become rent-seekers.
Any evaluation of the security of the system has to take the whole socio-technical system into account. Too many blockchain enthusiasts focus on the technology and ignore the rest.