The author is asking for OpenStack to "Implement transparent APIs from AWS, Azure, GCP for OpenStack"

There _was_ an EC2 API that OpenStack nova had back in the day, that became unmaintained and was eventually removed

http://cloudscaling.com/blog/openstack/the-future-of-opensta...

This blog was from 2015, and the end result was that nobody was willing to step up and do the hard work of creating these API compatibility layers.

Frankly, there were barely enough resources being put in by large companies, to keep the OpenStack APIs themselves well maintained.

So, I think the issue of OpenStack was that everyone suddenly decided to shift to containers, instead of VMs for their deployments, and OpenStack no longer was required.