Data centers in general are NOT a dying breed, and it's more a case of rapidly growing, not dwindling. Perhaps you are referring to individual companies moving to the cloud, and colo type activity (albeit institutions with strict regulation may still require a backup colo) dwindling?

However, the cloud resource providers are definitely growing (https://www.statista.com/outlook/tmo/data-center/worldwide#r...), and there is a huge push for more power and heat efficient architecture, whether on the server/network/supporting infrastructure side.