Any IT dept with less than 5-10 DBAs will have to throw out the window any Segregation of Duties plans (keeping apart access on Prod-Dev-QA) or separating/dedicating DBAs to the three different environments.
But the backup, hell yeah, you NEED mitigating controls (preventive/corrective) for when you allow people to make changes in Prod that haven't been gone through all the testing phases.
That's the problem with DevOps / CI/CD. The DBA team, and separation of duties / least privilege more generally, are seen as old-fashioned impediments to business velocity. The foundations of DevOps are supposed to be trust, tools, and testing, but in my experience once the dev team gets their hands on the tools, that's all she wrote.
To be fair, when you have a tech department of 6 people, who still have to respond to internal support tickets, manage the businesses intranet, and continue development of current projects, not to mention only 2 of those 6 have any clue how to setup/administrate a database... You can see the issue.
You can't just say "Hire more people" because the current setup is "working" and isn't considered critical to the rest of the business when it isn't tech related.
But the backup, hell yeah, you NEED mitigating controls (preventive/corrective) for when you allow people to make changes in Prod that haven't been gone through all the testing phases.