> I guess because it's by the IPFS developers

And is intended to run on an IPFS network. After reading the replies to this comment, I started looking into Sia, and wanted to try it out, but it seems that I first have to buy some Sia before even being able to become a host (!), which is an instant turnoff.

At the same time, I am already able to try out IPFS and have been able to develop apps using it for quite some time. I am not sure what the plans are with Filecoin, but IPFS also has a default-public (hosting) use case, while as of now Siacoin has private-only.