The goal of both agile and DevOps approaches is to get value to your customers/users as quickly as possible so if your development team is still toiling away for six months with no release are you really gaining benefit from either approach?
From observation, there are many organisations out there that have yet to benefit fully from DevOps because they still retain impediments in their processes and so have not truly implemented a DevOps culture into their organisation even though they employ “DevOps Engineers” and are using a grab bag of approaches – CI/CD, IaC, monitoring et al that are often considered ‘DevOps practices’. It seems like there is still a long way to go before DevOps is done well and extensively.
So if this is true why are people asking the questions? I think the answer can be found in the technology adoption lifecycle:
Craig Chelius, CC BY 3.0, via Wikimedia Commons
All technological approaches go through the same process and DevOps is no exception. More organisations who develop software than not have adopted at least some DevOps practices at this point and so adoption is well to the right of this graph – in other words it has normalised.