As title.

Case 1: I have multiple setup steps to do before doing the actual thing. The setup steps doesn't depend on each other, each one takes some time to complete and all of the setup steps are not resource intensive. E.g. Package manager download dependencies and setup gcloud doesn't depend on each other, they can be done in parallel.

Case 2: https://ideas.circleci.com/cloud-feature-requests/p/savecache-should-be-backgroundable

If I can do steps in parallel, I can save a lot of time from waiting for workflow complete.