Exactly and for many of the reasons you enumerated. I personally believe SiaCoin is on its way to be a decent provider of this technology.
For example, they recently enabled a feature where your data may be distributed to whitelisted hosts which one may limit to a certain geographic area such as CONUS if you happen to be in the states. This should help reduce latency for retrieval.
The host algorithm penalizes for downtime so this should translate to HA as there is an economic incentive.
For redundancy, the data is distributed to up to 21 hosts and up to 7 can fail and the data still be recoverable.
There is so much more the Sia network has to offer and have had my eyes in it for Steem as a markdown blog storage solution.
I think this would be more ideal than building from the ground up personally and the benefit should be explored.
I looked recently at their whitepaper and for me the crypto-economy of Sia (which has nothing to do with the technical prowess involved in providing cheap reliable storage) sucks big time.
On the contrary, the Crypto-economy is Steem's strong suit. So in my opinion combining the Sia technical solution with the steem crypto-economics could prove a real winner