I don't see how this is better than IPFS/Filecoin to be honest.
Solid is decentralised, not distributed,
it uses the classic client/server model rather than allowing anybody to be a peer.
It reminds me of Friendica and Diaspora, which are decentralised alternatives to Twitter/Facebook. They never really took off outside of a niche audience.
The main alternatives to Solid right now are IPFS/Filecoin, Ethereum's Swarm, MaidSafe, Zeronet. These are all distributed rather than just decentralised, but IPFS has by far the most backing (Filecoin was the #1 biggest ICO with
$257MM raised, Cloudflare recently launched an
IPFS gateway, Mozilla Firefox recently
added support for the IPFS protocol, etc).
IPFS is an extension of BitTorrent technology - it allows anybody to be a peer and seed a website/file/app/whatever to keep it online. There are already a number of websites built on IPFS technology, static files are easy to host and even
decentralised databases can be done too. But the real clincher that will ensure IPFS takes off is Filecoin, which is the incentive layer.
Right now theoretically anybody can be a peer and seed a website, keeping it online.
But why would you want to? That's where Filecoin comes in. You download the Filecoin software to your computer and choose how many mega/giga/terabytes of disk space you want to share with the Filecoin network, and you'll automatically be paid in Filecoin for sharing this disk space for hosting others files.
There's a similar competitor to Filecoin called Sia, which hasn't got nearly the same popularity but hosting 1GB on there is already only 10% the cost of hosting 1GB on Amazon S3 (which would be the centralised analogue).
Filecoin is still under development and is being launched in the next 3-6 months. I expect that already due to the mass popularity behind IPFS it will quickly get many hosts signing up and that drives the cost of storage way down, likely soon to only 1% of the cost compared to using centralised hosting like Amazon S3.
This means that suddenly
everybody will want to host
everything on Filecoin/IPFS because it's so much cheaper than using Amazon/Google/or their own servers. Since the barrier to entry for becoming a Filecoin host is so low (just download the client software) the network effect is massive, and it forces corporations to compete with each other and switch to make massive savings.
And that's how the decentralised web will once again become a de facto standard, by giving corporations every financial incentive to switch.