The same thing you get from AWS WorkSpaces, but in CLI form: a machine that's running within/adjacent to your corporate VPC, with fast high-bandwidth access to all your internal infrastructure, especially things like storage buckets. As opposed to your own machine, running half-way across the country where you might only be able to achieve 10Mbps between you and the AWS datacenter.

Think "I'll run this arbitrary script to batch-process input-bucket X to output-bucket Y, enriching the data by calling out to internal service Foo and external service Bar." The kind of thing Google's Cloud Dataflow is for, but one-off and freeform.

—also, for a lot of people, just the fact that things are running in the cloud, means they're running more reliably. If you want to run something that's going to take four days to finish, you don't want to do it on your own workstation. What if the power cuts out in your house? (Just the fact that you can restart/OS-update your local computer and "keep your place" in the remote is nice, too.) You want a remote VM somewhere (preferably with live migration in case of host maintenance) running screen(1) or tmux(1), with your job inside it. Of course, you can just create a regular VM in your VPC, and do it on top of that; but a cloud shell abstracts that away, and "garbage collects" after itself if you leave it idle.