That's nice but autoscaling mongodb clusters have been working for what, 5+ years at this point?
There are limits to what you can do safely with autoscaling, sure. But a datastore without that capability will never be a universal datastore that can cover all use cases.
I think it's far more likely we'll just discover that, indeed, no general solution exists, and that humans must take personal responsibility for tending to their digital gardens. We certainly have a lot of spam to weed out.