> Reselling AWS's offerings would cost more than running it on bare VM's, I'm sure they would be able to compete on price with them.

True -- I do think passing on the cost and taking a tiny margin with drastically reduced maintenance cost could be an attractive business model at scale though.

> It also doesn't make sense to rewrite their current software which is probably abstracted for multi-cloud to support re-selling.

I have no idea what their current software looks like, do you have any inside knowledge?

If they have abstracted, then they probably have multiple implementations of a similar API -- this is just changing one of them (or maybe even cloning it to reduce possibility of breakage). This might be as simple as just changing the AWS-specific provisioner to call out to AmazonMQ instead of EC2, or changing some code that generates terraform/pulumi scripts.

One thing I think they'd have to deal with is the fact that they support custom plugins that AmazonMQ may not.

The backups are also something that would differ greatly, along with metrics that rely on internal APIs which AWS may not provide access to.

Like other AWS products (RDS, Elasticache), there’s limitations since they provide protocol interoperability with proprietary tech behind the scenes.