But secondly, offline doesn't usually mean dead and gone, with unstable datacenters like this they are usually back online before the user has lost a full 25% of their redundancy.
Row level and rack level outages are handled by data randomization. The entire Sia system heavily depends on probabilistic techniques, both on the renting and hosting side. Row level failures will take out some of your data, but nobody should be disproportionately impacted by a cluster failure.
On Sia, each piece is at a different site. So 64-of-96 implies that each chunk of data (96 pieces to a chunk) is located in 96 different places. This doesn't help with the geo-bandwidth, but as discussed above there are other techniques to handle that.
Surprisingly, bandwidth pricing on the Sia network is even cheaper than storage pricing relative to centralized competition. That's a lot harder to model at scale though, so we aren't as confident the Sia bandwidth pricing will hold up at $1 / TB in the long term.
And technically, most of this stuff is customizable per-customer. If your particular use case has a different optimal parameterization, it's fairly easy to tune your client to suit your particular needs.
I mean this is basically the moment where I would expect every systems designer on HN coming out of the woods and crushing Sia into the ground, if there were, in fact, any ground at all to crush Sia into.
Is this actually legit? If so, where is the rejoicing? What am I missing?
At this point the cautious skeptic will be thinking "hmm, maybe there's something to this", not necessarily full on rejoicing.
That said, I agree it does seem promising. If you ever find yourself in need of cheap cloud storage it wouldn't hurt to look into Sia as a possible option.
Engineering is about tradeoffs. I could build a network as good as Google's with infinite money, infinite time, and infinite help. I could design a product as beautify as Apple's with the same lack of limitations. Unfortunately for me, I have limited money, limited time, and limited help. Every systems designer understands that, innately, so isn't rushing out of the woodword because Sia and Dropbox have merely chosen different tradeoffs. That one has IPO'd is uninteresting in the abstract. It's just money after all.
Reed-Solomon encoding adds 50%, of you want 3 block per 2 data blocks. Replicated encoding (not relevant here since this is allow throughput usecase, but necessary if you want to sustain high read throughput) is adding at least 200% (if you want a 3x replication, which I think should be the minimum).