If you’re paying Bay Area prices for engineers, $5K a month is a steal to not have to pay people to deal with sharding.
It'll run for ten years for next to nothing.
And you also need to have diverse routing for power coming in and generator / battery room set up.
I think the main issue is that the cloud providers don't publish much about outages that don't affect the end-user. I mean a failed hard drive happens all the time, but S3 is never affected by that.