They're all centralized now, though. It used to be that every medium-to-large business needed in-house networking expertise and ran their own small data centers

They're all centralized now, though. It used to be that every medium-to-large business needed in-house networking expertise and ran their own small data centers, or at least ran a server room that required a couple full-time people to manage. Now everything is cloud-hosted, and those kinds of jobs have all but vanished, unless you work at your regional AWS data center. Offices don't even need simple cable runs and switches/routers anymore. A basic consumer-level network connection and ISP-provided WiFi AP are all the vast majority of businesses need. Everyone has a laptop and there's nothing to plug in or manage.