One big difference is that your random uncle or sister-in-law can't just read about some trending startup and then semi-blindly invest a chunk of their life savings into it.

Financial regulations prevent the average nonexpert from making those kinds of risky investments in relatively unregulated companies - you have to qualify as an "accredited investor" (i.e. either someone with deep pockets or expertise in financial markets). Publicly traded companies and investment funds are open to anyone, but in exchange they're subject to all sorts of regulations about transparency and accounting rules to make it "safer" for the average Joe to invest in.

DAOs feel like they are really hoping to create an end run around all those financial protection laws.