How is Filecoin different from Sia coin? I remember a while ago hearing about both trying to decentralize storage but never kept up with it enough to really suss out the difference
Sia seems like a Dropbox/OneDrive replacement whereas Filecoin is an incentivized storage layer infrastructure for apps to use, especially dapps. If you wanted to build a decentralized SoundCloud you couldn't use Sia but IPFS/Filecoin is the primary building block of such a dapp.
If you do want something like Dropbox that is built on Sia, there is Filebase[4].
I am not associated with Sia at all. I've just been following their twitter for a while.
[1]: https://siasky.net/
[2]: https://nebulouslabs.github.io/skynet-docs/#introduction
[3]: https://twitter.com/SiaTechHQ/status/1291441690008592384