You know that if US East suffers a FULL data loss that the recovery would take weeks with the question if it would even be possible. That's what happened to ovh... it wasn't just one building.
Isn't that exactly what Availability Zones are for? They're physically separate[0] datacenters and each one contains a copy of each S3 object (unless using the explicit single-zone options)
It's also straightforward (although not necessarily that cheap) to replicate S3 objects to another region
OVH’s failure was a single building. That’s the problem with a lot of server hosters - even Google has their availability zones all co-located in the same building, so a physical event like a fire could take down an entire region. AWS has AZs in physically separate locations, each with 1+ separate DCs.