When I was running a Sia node pre-release it wasnt supposed to be for your average user, its a platform aimed at business users. Perhaps that message has got lost.
The one issue all these types of P2P systems have for businesses of course is anonymous users and the problems that causes due to legal obligations businesses have for KYC/AML.
So while I think your technical observations are maybe not so serious, there are non-technical, compliance issues that will need to be overcome.