I don’t find VMs to be that much easier to manage (in terms of rollback) than containers. The opposite in fact. VMs are these giant blobs that can be stateful or stateless or a mix of both. While containers have clear separation between the state (stored on volumes or in an external store like a db) and the “application” stored in immutable tags or digests.

Rolling back is easy as long as you understand where the state, if any, is which is actually the hard part of any application. At least with containers you have all of them stored in a well defined registry, while with VMs you would be rolling your own VM snapshot storage system. Not super complicated to do in the grand scheme of things, but it’s another thing you need to get right. But VMs/applications that can rollback would be just as easy (if not easier) to rollback with containers.