Especially for non-code configuration, like reports, dashboards, list views, etc, there are two different types of configuration: those that you absolutely need to have, and those you don't. If you're not sure, just ask yourself the question: "If someone accidentally deleted/modified this report/dashboard/list view/etc, would it reduce productivity, cause mistakes/errors to occur, or otherwise harm our business processes?"
If the answer is no, then it's certainly optional. However, if you answered yes, you should consider keeping a backup of those items mandatory. This is not to say that you need to source control every single dashboard, report, list view, etc, but if they're important to your business process, you definitely should back up these items.
And even if they don't go through a normal dev cycle (e.g. create in sandbox, store in repo, push to production), you might want to have a process where someone can build something in production, like a report, and request that it gets added to the backup. It's not uncommon to need to have a report available immediately instead of waiting for a dev cycle, but they might still be important enough to need to be backed up.