Ops people need a Dev environment to test, especially for Infrastructure as code. With an increased connectivity between developer code and Infrastructure, I prefer my team finds out everything in a development environment that's exactly like staging and prod. That way deployment to staging is proof of the IAC change. There's less risk.

This also lets developers try out new services in the cloud without impacting the staging... (This is on top of a sandbox for research, but integration of research takes time and an environment too)

I guess depends on the size of the company. How else would you constantly test integrations between different services? Especially if some services can't be easily ran on the laptop.

Also if you add terraform/ansible and all that jazz to the table. Where else? Infra team needs dev/stage as well.

It’s super useful to be able to spin up a dev environment for doing things like experimenting with the performance impact of different configs. It’d be annoying and potentially disruptive to other team members to do that on staging.

My company tasked me to mad dash their dev environment to AWS. Why? Because “cloud”, and perceived less risky than moving QA and Prod first.