What's the use case for something like "VMWare on Google Compute" is it just a API shim to translate VMWare API calls to GCE for companies that are trying to lift and shift to the cloud?
We use it, I'm not on the team that uses it. Basically a lift and shift of our backup data center which came with all sorts of improvements. It's quite a bit more expensive, the projects that it runs in cost more than the rest of our cloud costs in total. But the man hours we've done to set up those other cloud systems (Terraform) are much more costly.
It's a full managed (bare metal) VMware environment.
Basically you get a dedicated cluster of vSphere hosts, with VSAN storage.
Some use cases are: migrating to cloud (for all kinds of reasons, like not wanting to invest in own datacenters and HW anymore) without having to refactor applications, hybrid applications where the front end lives in Google Cloud but the backend requires a more 'traditional' environment, using the cloud for DR, ...