The world of Information Technology has changed a lot during my career, but in some ways, many things remain the same. There are still mainframes in use, and plenty of jobs. Lots of companies maintain their infrastructure in data centers, even though some are turning to private clouds for their infrastructure. There are plenty of jobs in that area as well.
There is a trend to consolidate resources into a bucket and then allocate those as needed for various applications and services. This is what mainframes do, albeit at a very high degree of reliability (and cost). The cloud seeks to replicate this, not with high reliability, but with redundancy, expecting systems to fail. In fact, plenty of the data centers these days involve a lot of similar hardware systems tied together with software, with failed systems being left in place rather than replaced.
This trend aims towards a lights-out data center, where humans don't work inside the location with servers. As someone that used to keep a coat by my desk in the summertime for trips inside the locked "computer room", it's a welcome trend. While a few people might actually need to check a cable or service an AC or UPS unit, most of us these days never see the systems we work on, whether those systems are owned by our company or rented in the cloud.
This doesn't mean that we won't have as much work. In fact, I think that most of the trends in computing over the last three decades have opened up opportunities for workers. This article talks about some of those changes that allow workers to morph along with technology to tackle different aspects of similar jobs. I certainly expect that anyone who wants to improve their skills and adapt to the new data center of the future to have plenty of work.
This reminds me of a scene from Aliens, where workers use enhanced suits to load heavy crates. I think this is the type of future I see, where humans work alongside new technology rather than being displaced by it. The need for humans to monitor, manage, adjust, and configure software systems and physically work alongside high-tech software is not going away anytime soon. The more that we adapt new technology, the more it seems that we add humans to work alongside it in some new way.
Continue to learn, adapt, and adjust your skillset and you can remain employed for a long time.